Pulmonary status of habitual cocaine smokers

Comparative study of pulmonary functions test among different substances abusers

BACKGROUND

Substance use is a problem that affects people all over the world and is prevalent in different age groups. The lungs in particular, with their unique exposure to the environment and the bloodstream, are vulnerable to damage from substance use and can affect lung function. Efforts have generally focused on cigarettes, while there is little research on different substances of use. The study aimed to detect changes in pulmonary function tests in different substance users.

METHODS

An analytical cross-sectional study was carried out among different substance users at the Abdalaal Elidridi Psychiatric Hospital. A total of 60 adults were included: 16 cannabis users, 16 heroin users, 16 methamphetamine users, and 12 alcohol users. Participants used only one substance. Height and weight were measured, and BMI was calculated. For each participant, pulmonary function tests (PFTs) including forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC ratio and peak expiratory flow rate (PEFR) were measured using an electronic spirometer, and the results were compared with normal reference values for Sudanese subjects matched for age, sex, and height.

RESULTS

A high prevalence of lung function abnormalities (100.0%) is seen in all abusers. Obstructive lung disease is found in 80.0% of patients, and restrictive lung disease is found in 20.0% of cases. The measured FEV1/FVC ratio in different substance groups was lower than the expected normal values of (88.2 ± 2.9%). The mean FEV1/FVC ratio of alcohol was (83.6 ± 7.6%), for heroin, it was (77.3 ± 15.8%), for methamphetamine, it was (77.7 ± 17.8%) and for cannabis, it was (71.03 ± 11.3%), the latter was significantly lower than the other two groups (P < 0.001). Duration of substance use was inversely correlated with the FEV1/FVC ratio (r = -0.378, P 0.001), indicating that a longer duration of substance use correlates with lower FEV1/FVC ratios.

CONCLUSIONS

Obstructive lung abnormalities are frequent in substance abusers. All types of substances have a major deleterious effect on PFTs and harm the respiratory system. More action should be taken to address the effects of substances on the lungs. Awareness, early detection, and intervention are essential.

Cracking the Opium Den: Cardiothoracic Manifestations of Drug Abuse

Recreational drug use is increasing worldwide, with emergency room visits and total deaths from drug overdose rising in recent years. Complications from prescription and recreational drug use may result from the biochemical effects of the drugs themselves, impurities mixed with substances, or from causes related to the method of drug administration. The presentation of drug overdose may be complex due to multisubstance abuse, including cigarette smoking and alcoholism, and can impact any organ system. Patients may present without history, and radiologists may be the first clinicians to suggest the diagnosis. We aim to explore the cardiothoracic manifestations of drug abuse and their multimodality imaging manifestations.

[Pulmonary complications in cocaine users]

Cocaine can be responsible for many psychiatric and/or somatic disorders. The aim of this systematic literature review of data was to expose relations between cocaine use and pulmonary complications. Cocaine can be responsible for acute respiratory symptoms (cough, black sputum, hemoptysis, dyspnea, wheezing, chest pain) and for various pulmonary disorders including barotrauma (pneumothorax, pneumomediastinum, subcutaneous emphysema, pneumopericardium), airway damage, asthma, bronchiolitis obliterans with organizing pneumonia, acute pulmonary edema, alveolar hemorrhage, alveolar pneumonia with carbonaceous material, bullous emphysema, acute eosinophilic pneumonia, pulmonary granulomatosis caused by talc or cellulose, interstitial pneumonitis and pulmonary fibrosis, vasculitis, pulmonary hypertension, pulmonary embolism and pulmonary infarction, mycotic pulmonary arterial aneurysms, septic emboli, aspiration pneumonia, community-acquired pneumonia, HIV-related opportunistic infections, latent tuberculosis infection, pulmonary tuberculosis, lung cancer and crack lung. Some of these complications are serious and may have a fatal outcome. Pulmonary function tests, thoracic tomodensitometry, bronchial fibroscopy with bronchoalveolar lavage and lung scintigraphy may be an aid to the diagnosis of these pulmonary compications. Cocaine use must be sought in case of respiratory symptoms in young persons.

Up in smoke: An unusual case of diffuse alveolar hemorrhage from marijuana

Diffuse alveolar hemorrhage (DAH) can be a serious and life threating condition. Illicit substance use has been associated with DAH, with cocaine being the most widely reported. Marijuana use has been associated with pulmonary complications in the form of pneumomediatsium, pneumothorax, bullous disease, and pulmonary aspergillosis. We present a case of diffuse alveolar hemorrhage (DAH) resulting from marijuana inhalation, a finding rarely described in the literature.

A 21-year-old male presented with several episodes of hemoptysis after drinking alcohol and smoking marijuana. He reported smoking 5–8 joints per day of marijuana (he denied use of bongs or other inhalant aids). His respiratory exam revealed bilateral fine rales. Laboratory evaluation included leukocytosis with left shift, normal platelets, coagulation profile, and a urine toxicology screen positive for tetrahydocanabinoid (THC). Chest CT revealed bilateral diffuse alveolar infiltrates suggestive of DAH. A bronchoscopy with BAL of bilateral upper lobes consistent with DAH with negative microbiologic studies, hemosiderin laden macrophages were present. Additional workup included a normal Echocardiogram, negative autoimmune serologies. His hemoptysis resolved with supportive care.

DAH is a potentially fatal disease that has been associated with illicit substance use, most commonly cocaine. Recently, reports have surfaced associating marijuana use with DAH, though these cases have all involved the use of bongs or other inhalant aids, leading to the hypothesis that combustibles and inhaled particles may be the etiologic factor. This is the second report of DAH developing after smoking only marijuana, though the etiology for the association between marijuana use and DAH remains uncertain.

The Cardiovascular Effects of Cocaine

Cocaine is the leading cause for drug-abuse-related visits to emergency departments, most of which are due to cardiovascular complaints. Through its diverse pathophysiological mechanisms, cocaine exerts various adverse effects on the cardiovascular system, many times with grave results. Described here are the varied cardiovascular effects of cocaine, areas of controversy, and therapeutic options.

Acute Pulmonary Injury after Inhalation of Free-Base Cocaine: A Case Report

Introduction

Many patients presenting to urban emergency departments (EDs) have chief complaints directly related to the use of illicit drugs. Given the reluctance of patients to admit to their use of cocaine, it is important for the emergency medicine provider (EMP) to recognize key epidemiologic principles as well as features of the history, physical examination, and diagnostic studies that suggest the sequelae of cocaine abuse.

Case Presentation

We describe our assessment of an otherwise healthy 47-year-old man with the acute onset of pleuritic chest pain accompanied by hypoxia, radiographic evidence of diffuse alveolar hemorrhage (DAH), and an elevated creatine phosphokinase (CPK) level. The patient vehemently denied active cocaine abuse. No clear pulmonary, cardiac, or infectious explanations for his signs and symptoms were readily apparent. Ultimately, after further workup and urine toxicology screening, the cause of this patient's chest pain and hypoxia was determined to be DAH related to his recent inhalation of crack cocaine. The patient was treated with systemic corticosteroids and improved.

Conclusion

Nearly 41% of patients who present to the ED because of complications of inhaled cocaine use are experiencing pleuritic chest pain, and more than half have an elevated CPK concentration. As many as 40% of these patients deny using the drug when asked. These data are important for EMPs to know when formulating a differential diagnosis for patients presenting with pleuritic chest discomfort.

Spirometry findings among drug users in the Indonesian National Narcotics and illicit drug Bureau Rehabilitation Center

BACKGROUND

The increasing prevalence of drug user in Indonesia is affecting the health sectors. The lungs health were affected by the use of the illicit drug. However, lung function among drug users is still unclear.

METHODS

This descriptive-analytic study involves 144 drug users who met the inclusion criteria. Chest X-ray was performed to identify the subject with pulmonary tuberculosis to exclude from the study. Subjects were then undergone spirometry test and interviewed using questionnaires.

RESULTS

One hundred and forty-four subjects were included in this study. One hundred and twenty-one (84.03%) were male and 128 subjects showed normal lung function. Proportion of abnormal spirometry was 10.4% (n = 15). The restriction was found in ten subjects, and obstruction was found in four subjects. There was significant correlation between the ratio of forced expiratory volume in 1 s to forced vital capacity (FEV₁/FVC) and age (P = 0.000; r = -0.454, moderate correlation), time of using cannabis (P = 0.01; r = -0.345, weak correlation), time of using methamphetamine inhalation (P = 0.004; r = -0.25, weak correlation), duration of using heroin injection (P = 0.025; r = -0.337, weak correlation), time of using cigarette (P = 0.000; r = -0.365, weak correlation), and the amount of cigarette consumption/day (P = 0.04; r = -0.238, weak correlation).

CONCLUSION

This study found that there was a weak correlation between declined FEV₁/FVC with a time of smoking, the amount of cigarette consume per day, time of cannabis inhalation, time of methamphetamine inhalation, and time of heroin injection.

Asthma associated with the use of cocaine, heroin, and marijuana: A review of the evidence

OBJECTIVE

A review of the evidence was conducted regarding asthma associated with the use of cocaine, heroin, and marijuana.

DATA SOURCES

A search of the English literature was performed via PubMed/Medline and EMBASE using the search terms asthma AND cocaine, heroin, and marijuana. When pertinent articles were found, salient references in those articles were assessed.

STUDY SELECTION

Due to the relatively small number of studies, we included all studies and cases.

RESULTS

For several decades, case reports, retrospective studies, and laboratory investigations have demonstrated that inhalation of cocaine or heroin is associated with increased asthma symptoms and reduced pulmonary function. Smoking crack cocaine, nasal insufflation of cocaine or heroin, and smoking heroin increases the risk of emergency department visits and hospitalizations for asthma. Although frequent smoking of marijuana may cause symptoms of cough, sputum production, and wheezing in the general population, more studies are needed specifically in patients with asthma. Smoking marijuana with concomitant tobacco use is common and further worsens the respiratory symptoms.

CONCLUSIONS

Use of cocaine and heroin in patients with asthma should be avoided. Pending further studies, it would be prudent for patients with asthma to avoid smoking marijuana. Clinicians need to be vigilant regarding use of these drugs in their patients with hyperreactive airway disease.

The Asthma-COPD Overlap Syndrome

Although in textbooks asthma and chronic obstructive pulmonary disease (COPD) are viewed as distinct disorders, there is increasing awareness that many patients have features of both. This article reviews the asthma-COPD overlap syndrome.

Stimulants and the lung : review of literature

Illicit stimulants, such as cocaine, amphetamine, and their derivatives (e.g., "ecstasy"), continue to exact heavy toll on health care in both developed and developing countries. The US Department of Health and Human Service reported over one million illicit drug-related emergency department visits in 2010, which was higher than any of the six previous years. Both inhaled and intravenous forms of these substances of abuse can result in a variety of acute and chronic injuries to practically every part of the respiratory tract, leading potentially to permanent morbidities as well as fatal consequences--including but not limited to nasal septum perforation, pulmonary hypertension, pneumothorax, pneumomediastinum, interstitial lung disease, alveolar hemorrhage, reactive airway disease, pulmonary edema, pulmonary granulomatosis, infections, foreign body aspiration, infections, bronchoconstriction, and thermal injuries. Stimulants are all rapidly absorbed substances that can also significantly alter the patient's systemic acid-base balance and central nervous system, thereby leading to further respiratory compromise. Mounting evidence in the past decade has demonstrated that adulterants coinhaled with these substances (e.g., levamisole) and the metabolites of these substances (e.g., cocaethylene) are associated with specific forms of systemic and respiratory complications as well. Recent studies have also demonstrated the effects of stimulants on autoimmune-mediated injuries of the respiratory tract, such as cocaine-induced midline destructive lesions. A persistent challenge to studies involving stimulant-associated respiratory toxidromes is the high prevalence of concomitant usage of various substances by drug abusers, including tobacco smoking. Now more than ever, health care providers must be familiar with the multitude of respiratory toxidromes as well as the diverse pathophysiology related to commonly abused stimulants to provide timely diagnosis and effective treatment.

Variations in FEV₁ decline over time in chronic obstructive pulmonary disease and its implications

PURPOSE OF REVIEW

This article reviews findings from longitudinal observational studies in both general and chronic obstructive pulmonary disease (COPD) populations, as well as from intervention trials in COPD, in which the annual rate of decline in forced expired volume in 1  s (FEV₁) has been measured. The purpose of the review is to describe the individual variability in rates of decline in FEV₁ within these populations, explore the factors contributing to this variability and discuss its implications.

RECENT FINDINGS

Individual rates of decline in FEV₁ have been found to vary considerably across participants with COPD in both observational cohorts and intervention trials from decreases as rapid as 150-200  ml per year to increases of up to approximately 150  ml per year, with mean rates of decline ranging from 33 to 69  ml per year. Aside from technical and biologic (e.g., time of day, season, weather, fatigue) sources of variation, other influential factors have included smoking status (most notably current versus former smoking), baseline smoking intensity, baseline lung function, airway hyperresponsiveness, exacerbation frequency, and, variably, age and sex. The presence of emphysema may also be a determinant, as well as certain biomarkers and gene variants.

SUMMARY

The wide distribution of individual rates of decline in FEV₁ includes especially rapid and slow declines. Future research is needed to identify biomarkers that both are predictive of a rapid decline within individuals who might then be targeted for special intervention and might also serve as surrogate endpoints in interventional trials.

Smoking cessation and environmental hygiene

Although there are nonmodifiable genetic risk factors for COPD, most known risk factors for development and progression of COPD can be corrected. Continued efforts to encourage smoking cessation and measures to reduce exposure to SHS, outdoor air pollution, biomass smoke, and occupational and related amateur exposures will have a significant impact on worldwide health.

Development of cocaine-induced interstitial lung damage in two CYP2C and VKORC1 variant allele carriers

BACKGROUND

Often, the connection between drug use and the development of related inflammatory damage or idiosyncratic toxicities is hard to recognize and objectify. The presence of cytochrome P450 (CYP) variant genotypes appears to be a substantial susceptibility risk factor in the development of drug-induced pulmonary adverse events. We hypothesized that the presence of variant alleles may be associated with serious complications of illicit drug use.

CASE REPORT

We report the cases of two cocaine users who developed a 'flu-like' syndrome with diffuse interstitial infiltrates after cocaine abuse. Genotyping for CYP (CYP2C9, CYP2C19) and vitamin K epoxide reductase complex 1 (VKORC1) allelic variants (-1639G/A and 1173C/T) was performed in these two patients. Both cases were heterozygous for VKORC1 variant alleles, and both possessed a CYP2C polymorphism (case 1: CYP2C19*1/*2; case 2: CYP2C9*1/*3).

CONCLUSIONS

The described drug abuse cases suggest that an association between the presence of CYP2C and VKORC1 allelic variants and cocaine-induced interstitial lung damage is highly likely. It is assumed that these polymorphisms contribute to intra-individual variability in drug response and toxicity, including cocaine response and toxicity. Moreover, the importance of including pharmacogenomics in the work-up of patients with suspected drug-induced (lung) toxicity, such as alveolar hemorrhage, is highlighted by these cases.

Effects of chronic exposure to crack cocaine on the respiratory tract of mice

Smoked cocaine (crack cocaine) causes several forms of injury to the respiratory tract, including asthma exacerbations, lung edema and hemorrhage, and nasal mucosal alterations. Few studies, however, have assessed respiratory tract pathology in habitual users of crack cocaine. Here, we describe the histological alterations in the respiratory tract of mice caused by chronic inhalation of crack cocaine. Twenty 2-month-old BALB/c mice were exposed to the smoke of 5 g crack cocaine in an inhalation chamber once a day for two months and compared to controls (n = 10). We then morphometrically analyzed nose and bronchiolar epithelial alterations, bronchiolar and alveolar macrophage cell density, alveolar hemosiderin content, and in addition determined the vasoconstriction index and the wall thickness of pulmonary arteries. The serum cocaine level was 212.5 ng/mL after a single inhalation. The mucus content of the nasal epithelium increased in crack-exposed animals, and the nasal and bronchial epithelium thickness decreased significantly. The alveolar hemosiderin content and the alveolar and bronchiolar macrophage cell density increased in animals exposed to crack. The vasoconstriction index increased in the pulmonary arteries of the exposed group. Chronic crack cocaine inhalation causes extensive histological changes along the entire respiratory tract.

Pulmonary complications of crack cocaine use: high-resolution computed tomography of the chest

Here, we report high-resolution computed tomography (HRCT) findings in a patient who developed sudden hemoptysis, dyspnea and chest pain after smoking crack cocaine. Chest X-rays showed consolidations, primarily in the upper lobes, and HRCT scans showed ground glass attenuation opacities, consolidations and air-space nodules. A follow-up CT, after drug use discontinuation and administration of corticosteroids, showed partial resolution of pulmonary lesions and the appearance of cavitations. Clinical, imaging and laboratory findings led to a diagnosis of 'crack lung'.

Acute inhalation exposure to vaporized methamphetamine causes lung injury in mice

Methamphetamine (MA) is currently the most widespread illegally used stimulant in the United States. Use of MA by smoking is the fastest growing mode of administration, which increases concerns about potential pulmonary and other medical complications. A murine exposure system was developed to study the pulmonary affects of inhaled MA. Mice were exposed to 25-100 mg vaporized MA and assessments were made 3 h following initiation of exposure to model acute lung injury. Inhalation of MA vapor resulted in dose-dependent increases in MA plasma levels that were in the range of those experienced by MA users. At the highest MA dose, histological changes were observed in the lung and small but significant increases in lung wet weight to body weight ratios (5.656 +/- 0.176 mg/g for the controls vs. 6.706+/- 0.135 mg/g for the 100 mg MA-exposed mice) were found. In addition, there was 53% increase in total protein in bronchoalveolar lavage (BAL) fluid, greater than 20% increase in albumin levels in the BAL fluid, greater than 2.5-fold increase in lactate dehydrogenase levels in the BAL fluid, and reduced total BAL cell numbers (approximately 77% of controls). Levels of the early response cytokines tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 were dose-dependently increased in BAL fluid of MA-exposed mice. Exposure to 100 mg MA significantly increased free radical generation in the BAL cells to 107-146% of controls and to approximately 135% of the controls in lung tissue in situ. Together, these data show that acute inhalation exposure to relevant doses of volatilized MA is associated with elevated free radical formation and significant lung injury.

Outcomes of cocaine-induced gastric perforations repaired with an omental patch

Crack cocaine has been associated with acute gastric perforation. The appropriate surgical treatment and long-term outcomes remain unclear. A retrospective chart review of all gastroduodenal perforations associated with crack cocaine use was performed. Data abstracted included details of short- and long-term outcomes. Kaplan-Meier methods were used to evaluate surgical outcomes. Over the 14-year period ending December 2005, 16 cases of crack-induced gastric perforations were identified. Most (75%) were treated with an omental patch. The other patients underwent a formal antiulcer operation, including one vagotomy and pyloroplasty (V&P), one vagotomy and antrectomy, one subtotal gastrectomy, and one ulcer excision and V&P. All patients after antiulcer procedures were followed for a median of 63 months (range 27-120) with no recurrences. Follow-up data were available in 75% of the omental patch patients. Recurrence of disease was observed in 56% of these omental patch patients at a median of 20 months (range 11-39). Those without recurrence were followed for a median of 67 months (range 12-96). The recurrence rate was borderline lower in the antiulcer group (P = 0.072). Omental patch closure results in a recurrence rate over 50% compared with no recurrence for formal antiulcer procedures.

Pulmonary complications from cocaine and cocaine-based substances: imaging manifestations

Cocaine is the illicit drug whose abuse most often results in cardiopulmonary symptoms and emergency treatment. Habitual smoking of alkaloidal cocaine ("freebase," "crack") has replaced nasal insufflation as the most common method of abuse. Smoking of cocaine exposes the lung directly to the volatilized drug as well as to the other combustion products of the smoked mixture, thereby increasing the risk of adverse pulmonary effects. A wide variety of pulmonary complications including interstitial pneumonitis, fibrosis, pulmonary hypertension, alveolar hemorrhage, asthma exacerbation, barotrauma, thermal airway injury, hilar lymphadenopathies, and bullous emphysema may be associated with the inhalation of crack cocaine or of associated substances such as talc, silica, and lactose. Cocaine abuse represents one of the most serious medical and social problems of our time. Radiologists should be familiar with the various pleuropulmonary complications associated with the abuse of illicit drugs in general and of cocaine in particular to ensure correct diagnosis and appropriate treatment planning in patients with respiratory manifestations associated with such abuse.

An overview of non-cardiac cocaine toxicity

Cocaine use in the United States continues to be a significant problem. Cocaine use is responsible for approximately 143,000 Emergency Department visits annually. The cardiac effects of cocaine are well known and much is written on this topic; this is beyond the scope of this article. Cocaine use is also responsible for a variety of non-cardiac, systemic complications, which it is our purpose to review. Multiple systemic effects of cocaine are seen with both acute and chronic use. These systems include: psychological and psychiatric, neurological, renal, pulmonary, gastrointestinal, obstetrical, and otolaryngological.

Emergency department utilization by crack-cocaine smokers in Dayton, Ohio

The objective of this study was to determine the frequency, principal diagnoses, and correlates of emergency department (ED) visits made by persons with a history of crack-cocaine use (n = 333) over a 3-year period. Data were collected from participant self-reports and hospital records. During the study a total of 643 ED visits were made by 211 people, ranging from 53.5 to 76.7/100 persons/year. Injury and poisoning accounted for the largest single category of ED visits (29.5%). Men had lower odds of visiting the ED (OR=0.79, 95%CI=0.62-0.99), as did participants with higher levels of education (OR=0.83, 95%CI=0.73-0.94). Number of times in drug abuse treatment (OR=1.04, 95%CI=1.01-1.09), having a chronic disease (OR=1.46, 95%CI=1.06-1.99), and higher Addiction Severity Index composite medical scores (OR=1.62, 95%CI=1.15-2.29) increased the odds of an ED visit. Factors in addition to drug use are likely to affect ED utilization rates among crack-cocaine smokers.

Challenges in the adoption of new pharmacotherapeutics for addiction to alcohol and other drugs

The adoption of pharmacotherapies for the treatment of alcohol and drug use disorders has progressed slowly despite the approval of new and effective medications. This paper begins with overviews of the prevalence of alcohol and drug abuse and dependence, the costs of addiction to the nation, and the value of treatment services. The role of pharmacotherapy in the treatment of addictive diseases is examined, and factors that affect the adoption and use of medications for alcohol and drug treatment are identified and discussed. Investigations that tested the effectiveness of buprenorphine for treatment of opioid dependence in new settings illustrate physician and counselor training and mentorship strategies that may promote the adoption of medications in the treatment of alcohol and drug use disorders. The paper concludes with a discussion of barriers and ways to surmount the barriers and to foster greater use of medications in alcohol and drug treatment.

Pulmonary alterations in cocaine users

CONTEXT

Brazilian researchers have recently recognized a marked increase in the number of people using abusable drugs and the consequences of this habit. It has become a major public health problem in a potentially productive segment of the general population. In the last few years, several medical articles have given special emphasis to pulmonary complications related to cocaine use. This review is based on this information and experience acquired with groups of cocaine users.

OBJECTIVE

To present to physicians the pulmonary aspects of cocaine use and warn about the various effects this drug has on the respiratory system, stressing those related to long-term use.

DESIGN

Narrative review.

METHOD

Pulmonary complications are described. These may include infections (Staphylococcus aureus, pulmonary tuberculosis, acquired immunodeficiency syndrome/aids, etc.), aspiration pneumonia, lung abscess, empyema, septic embolism, non-cardiogenic pulmonary edema, barotrauma, pulmonary granulomotosis, branchiolitis obliterans and organizing pneumonia, pneumonitis and interstitial fibrosis, pneumonitis hypersensitivity, lung infiltrates and eosinophilia in individuals with branchial hyperreactivity, diffuse alveolar hemorrhage, vasculitis, pulmonary infarction, pulmonary hypertension and alterations in gas exchange. It is concluded that physicians should give special attention to the various pulmonary and clinical manifestations related to cocaine use, particularly in young patients.

Chasing the dragon, related to the impaired lung function among heroin users

AIM

To describe the pulmonary function and prevalence of dyspnoea among methadone patients and to study the relation with exposure to heroin by inhaling.

STUDY POPULATION

A sample of 100 patients from methadone maintenance treatment (84% male, average age 42 years).

MEASUREMENTS

Questionnaires were used to measure life-time exposure to heroin, cocaine, cannabis, tobacco, and symptoms of dyspnoea. Spirometry was performed and residual difference of measured FEV(1) from the age, sex, height and ethnicity predicted value (delta FEV(1)) was used as a main outcome parameter.

FINDINGS

The median delta FEV(1) was -0.26 l (inter quartile range -0.70; +0.12). Twenty per cent experienced dyspnoea while 'walking at a normal pace with someone of their own age'. History of cigarette smoking was reported by 98%; heroin smoking by 88%. Multiple linear regression analysis showed a statistically significant association between heroin-smoking and delta FEV(1), logistic regression analysis showed an association between heroin-smoking and prevalence of dyspnoea.

CONCLUSIONS

Chronic heroin smoking seems to be related to an impaired lung function and higher prevalence of dyspnoea. However, part of the observed lung function impairment will be caused by tobacco smoking. Further research is needed to quantify the effect of heroin smoking and disentangle the effect of smoking heroin and tobacco.

Sinopulmonary complications of illicit drug use

Illicit drug use is frequently complicated by sinopulmonary illnesses. These complications fall into two major categories: (1) direct effects of drug exposure, and (2) indirect effects caused by HIV-induced immunosuppression. This article reviews the more common sinopulmonary syndromes associated with illicit drug use.

Chronic and acute effects of "crack" cocaine on diffusing capacity, membrane diffusion, and pulmonary capillary blood volume in the lung

STUDY OBJECTIVES

To evaluate possible alterations in the diffusing capacity of the lung for carbon monoxide (DLCO) or its components, membrane diffusing capacity of the lung for carbon monoxide (DMCO) and pulmonary capillary blood volume (Vc), in habitual smokers of "crack" cocaine (with or without tobacco) and following the short-term administration of inhaled cocaine base or IV cocaine HCl.

DESIGN

Cross-sectional and longitudinal evaluation of DLCO and its components in smokers of cocaine alone, tobacco alone, and cocaine plus tobacco, and in nonsmokers and ex-smokers. Measurement of possible acute effects on DLCO and its components after experimental short-term administration of IV and smoked cocaine.

SETTING

University and Veterans Affairs hospital research laboratories.

PARTICIPANTS

Convenience sample of habitual smokers of crack cocaine with or without tobacco and matched control nonsmokers and ex-smokers, and smokers of tobacco only.

MEASUREMENTS

DLCO, DMCO, and Vc.

CONCLUSIONS

Neither habitual cocaine smoking in cross-sectional or longitudinal analysis nor the short-term administration of inhaled alkaloidal cocaine significantly affected DLCO or its component parts. In contrast, a clear cross-sectional effect of regular tobacco smoking was demonstrated.

Evidence of chronic damage to the pulmonary microcirculation in habitual users of alkaloidal ("crack") cocaine

STUDY OBJECTIVE

To evaluate BAL cells obtained from habitual users of alkaloidal ("crack") cocaine alone or in combination with tobacco, for evidence of cocaine-associated alveolar injury.

DESIGN

Prospective cohort study.

PATIENTS

A total of 36 healthy men and women (mean age [SD], 37.5 [7.5] years), including 10 cocaine-only smokers (CS), 6 cocaine-plus-tobacco smokers (CTS), 10 tobacco smokers (TS), and 10 nonsmokers (NS), underwent fiberoptic bronchoscopy and BAL.

METHODS

Cytospins were prepared from BAL cells and stained with Wright-Giemsa for cell differentials and Gomori's stain for detection of hemosiderin. Endothelin (ET)-1 levels were determined from lavage fluid by enzyme-linked immunosorbent assay.

RESULTS

None of the cocaine users reported episodes of hemoptysis or respiratory distress, and routine spirometry findings were within normal limits in all subjects. While there was little effect on total cell numbers or differential counts, the percentages of hemosiderin-positive alveolar macrophages (AMs) were markedly increased in CS (33.8 +/- 8.7% [SEM]) compared to TS and NS (< 2%; p < 0.05). The percentages of hemosiderin-laden AMs were also numerically increased in CTS (11.8 +/- 7.8%), but this value was not statistically significant from that of TS or NS. ET-1 levels were significantly increased in the fluid recovered from CS (6.2 +/- 0.8 pg/mL) when compared to NS (1.2 +/- 0.4 pg/mL) and TS (1.3 +/- 0.2 pg/mL) [p < 0.05], while ET-1 levels were elevated to a lesser extent in CTS (2.5 +/- 0.6 pg/mL). ET-1 levels correlated with the percentage of hemosiderin-positive AMs when CS were analyzed in conjunction with CTS (r = 0.64; p = 0.0004).

CONCLUSION

Clinically inapparent alveolar hemorrhage occurs frequently in otherwise healthy crack cocaine smokers and is associated with elevated levels of ET-1, indicative of cocaine-induced pulmonary microvascular injury.

Bronchial hyperreactivity in patients who inhale heroin mixed with cocaine vaporized on aluminum foil

BACKGROUND

In our area, inhaling heroin mixed with cocaine vaporized on aluminum foil, known as rebujo, is becoming more and more common.

AIM

To define the prevalence and the characteristics of bronchial disease (wheezing, bronchial hyperreactivity [BHR], and asthma) present in subjects inhaling heroin mixed with cocaine vaporized on aluminum foil.

MATERIALS AND METHODS

Ninety-one subjects who inhaled the drug mixture were included in the study: 62 subjects were from a drug rehabilitation center (INH-I group), and 29 subjects were among patients admitted to our hospital for a variety of reasons (INH-II group). A questionnaire was completed in both groups, as well as IgE determination and lung function tests (spirometry and methacholine challenge). The control group consisted of 122 individuals who did not inhale the drug mixture, and were chosen randomly from the general population (NO-INH group). All subjects were tobacco smokers.

RESULTS

In the INH-I group, there was a 41.9% prevalence of wheezing over the past 12 months, a 44.4% prevalence of BHR, and a 22.02% prevalence of asthma, defined as wheezing plus BHR. In the NO-INH group, these values were 32.78% (p = 0.22), 15.57% (p < 0.0001), and 8.19% (p < 0.01), respectively. Of the subjects who inhaled the drug mixture and denied having symptoms prior to the use of the drug mixture, 31.4% had wheezing develop after commencing use of the drug, following a mean latency of 4.09 months. Wheezing remitted in only 7.6% after discontinuation of the drug.

CONCLUSIONS

(1) There is a real increase in BHR in subjects who inhale heroin mixed with cocaine vaporized on aluminum foil; and (2) this BHR is associated with wheezing that develops after a variable period of latency, once drug inhalation begins, and persists despite discontinuation of the drug.

Characteristics of injection drug users who utilize tuberculosis services at sites of the Baltimore city needle exchange program

OBJECTIVE

To describe characteristics of needle-exchange program (NEP) participants who utilized tuberculosis services from an NEP site.

METHODS

Between June 1998 and May 1999, tuberculosis services were advertised and offered to Baltimore, Maryland, NEP participants. Demographic and tuberculosis-specific data were collected on participants who self-selected into services. Analyses were based on being tuberculin skin tested, returning for a skin test reading, and testing tuberculin positive.

RESULTS

Among 691 contacts with NEP participants, this service performed 296 tuberculin tests, with an 84% return rate for skin test reading. Participants were 32% female, 87% African American, and 11% employed. Higher frequency of NEP visits was positively associated with requesting tuberculosis services and returning for skin test reading. Among those who returned for skin test reading, longer smoking duration and problems getting food in the past year due to a lack of money were associated with a positive test.

CONCLUSIONS

Utilization of a tuberculosis service and high return rates can be achieved among NEP participants without formal recruitment strategies. Frequent exchange appears to facilitate return visits for NEP-based tuberculosis screening, which may imply accessibility for frequent exchangers. More extensive health services at sites of the Baltimore NEP appear to be warranted, with particular attention paid to effectiveness for frequent exchangers.

Increased lower respiratory tract iron concentrations in alkaloidal ("crack") cocaine users

STUDY OBJECTIVE

We hypothesized that the use of inhaled alkaloidal ("crack") cocaine could increase lung content of iron, either by inducing alveolar hemorrhage or by other mechanisms. Intrapulmonary accumulation of iron could promote chronic lung diseases in crack users. The goal of this study was to determine whether iron and ferritin content of alveolar macrophages or fluid recovered by BAL was increased in subjects using crack, compared with nonsmokers.

METHODS

BAL was performed in 31 volunteer subjects, including healthy nonsmokers (n = 7), subjects smoking crack alone (n = 7), as well as subjects smoking both crack and cigarettes (n = 7) or cigarettes alone (n = 10). Iron content of alveolar macrophages and BAL fluid was determined by a colorimetric method and ferritin content of alveolar macrophages, and BAL fluid was measured by a two-sided immunoradiometric method.

RESULTS

Alveolar macrophages recovered from crack users contained more iron than did alveolar macrophages from nonsmokers (25.4 +/- 2.9 nmol/10(6) vs 5.5 +/- 0.6 nmol/10(6) [mean +/- SE]; p < 0.01). There were similar increases in alveolar macrophage ferritin as well as BAL fluid iron and ferritin in crack users, compared with nonsmokers. BAL fluid ferritin concentrations in subjects smoking both crack and cigarettes were increased, compared with subjects smoking crack alone or cigarettes alone (p < 0.05).

CONCLUSIONS

Use of crack increases intrapulmonary concentrations of iron and ferritin. Effects of crack on extracellular ferritin concentrations may be additive with effects of cigarette smoking. Although the mechanism(s) causing pulmonary iron accumulation were not identified by this study, it may be a result of occult alveolar hemorrhage or increased vascular permeability. The increase in lung iron burden in habitual crack users could promote chronic lung diseases in these subjects.

Cocaine, HIV, and their cardiovascular effects: is there a role for ACE-inhibitor therapy?

Cocaine abuse and HIV disease each have potentially adverse effects upon the heart and cardiovascular system which may be exacerbated when these risk factors are combined. The development of a safe and effective agent to treat both cocaine addiction and its cardiovascular sequelae, that is well-tolerated by HIV patients, would thus be of considerable clinical utility. In this article we discuss the rationale for the investigation of angiotensin converting enzyme (ACE) inhibitors, commonly used to treat hypertension, for treatment in cocaine-abusing populations, based on their potential to reduce cocaine use by modulating levels of dopamine and corticotropin releasing factor in the brain, and on their ability to reverse cardiovascular and platelet abnormalities. We present preliminary findings from echocardiographic and platelet activation studies in 16 HIV-positive, cocaine abusing patients, as well as tolerability and efficacy studies of the ACE-inhibitor, fosinopril, for the treatment of cocaine abuse in both HIV-positive (n=6) and HIV-negative (n=5) methadone-maintained cocaine abusers. Findings suggest that HIV-positive cocaine-abusing patients possess abnormalities of diastolic heart function and platelet activation that are potentially reversible with ACE-inhibitor therapy. Findings also suggest that fosinopril is well-tolerated regardless of HIV serostatus, does not appear to cause hypotension, and may possess effectiveness for reducing cocaine use. We conclude that ACE-inhibitor therapy may offer a new pharmacologic approach to the treatment of cocaine abuse and its complications, and that controlled research of this class of agents may be promising.

Longitudinal application of the medical outcomes study 36-item short-form health survey with not-in-treatment crack-cocaine users

BACKGROUND

The Medical Outcomes Study SF-36 has been used infrequently with substance abusers.

OBJECTIVES

The objectives of this study were to use the SF-36 to assess changes in the health status of crack-cocaine users over time, to determine the characteristics of users who change, to assess the influence of frequency of crack use on SF-36 health status, and to determine the utility of the SF-36 with crack users.

DESIGN

A multilevel model was used to analyze data that were collected every 6 months over a 2-year period.

SUBJECTS

The sample consisted of 439 not-in-treatment crack-cocaine users.

MEASURES

The SF-36 was administered at baseline and follow-up interviews. Data on the frequency of crack-cocaine use were also collected.

RESULTS

On average, SF-36 health status remained fairly static during the study although statistically significant increases in scores occurred on the social functioning and role-emotional subscales. Variation in subjects' health trajectories occurred but was not, for the most part, explained by individual characteristics. Frequency of crack use was negatively related to scores on the physical functioning, social functioning, and mental health subscales. Most subscales did not reflect what are commonly recognized to be the health-compromising effects of cocaine use, raising questions about the use of the SF-36 with illicit drug users.

CONCLUSIONS

Changes in crack users' SF-36 health status were uncommon. Frequency of crack use was negatively associated with health status. Several SF-36 subscales may be helpful in studies involving illicit drug users in which limited assessments of health status are needed.

Prevalence of cocaine use and its impact on asthma exacerbation in an urban population

OBJECTIVES

To assess the prevalence of cocaine use, and its impact on severity of presentation, among adults presenting to the emergency department (ED) with asthma. A secondary aim was to assess the use of various asthma treatment modalities, with reference to the 1997 National Asthma Education and Prevention Program (NAEPP) guidelines.

METHODS

All adults aged 18 to 55 years who presented to the ED of this institution with an asthma attack, were approached about participating in the study, which required giving informed consent, answering a facilitated questionnaire, and giving a urine sample for drug screening.

RESULTS

Patients were enrolled during a 7-month period. A total of 163 patients were approached to enter the study; 116 patients consented to participate in the study, with 103 submitting complete urine samples. Thirty-seven patients refused to participate, and 10 were excluded. Sixty-eight percent of the patients were women, with a mean age of 33 years. African-Americans made up 89% of the total group. Thirty-five percent were cigarette smokers. Urine cocaine tests were positive in 13 of 103 (13%); 6 of 103 (5.8%) were positive for opiates. In the cocaine-positive group, 5 of 13 patients (38%) were admitted to the hospital, including two patients requiring intubation and mechanical ventilation. Of the total group, 23 of 103 patients (22%) were admitted, and 5 of those 23 admitted patients (22%) were cocaine-positive. Length of stay was significantly longer (5 vs 2.5 days, p < 0.05) in the cocaine-positive admitted patients. Forty-six percent of all patients reported using inhaled corticosteroids (ICS), with 39% of admitted patients using them. Thirty-two percent of all patients had obtained three or more refills of their beta(2)-agonist inhaler in the previous month.

CONCLUSIONS

The prevalence of cocaine use may be much higher than the 13% shown in this study, because of patients' refusal to participate in the study. Second, the severity of exacerbation appears to be worse in the cocaine-positive group. Finally, the majority of patients presenting did not use ICS in accordance with the NAEPP guidelines.

Histopathologic and molecular alterations in bronchial epithelium in habitual smokers of marijuana, cocaine, and/or tobacco

BACKGROUND

Tobacco smoking has been observed to cause molecular alterations in bronchial epithelium that antedate the development of lung carcinoma. The rising prevalence of marijuana and cocaine use among young adults in the United States prompted us to investigate whether similar molecular and histopathologic alterations occur in habitual smokers of marijuana and/or cocaine who may or may not also smoke tobacco.

METHODS

Bronchoscopy was performed in 104 healthy volunteer subjects, including 28 nonsmokers and 76 smokers of one or more of the following substances: marijuana, tobacco, and/or cocaine. Bronchial mucosa biopsy specimens and brushings were analyzed for histopathologic changes, for immunohistopathologic expression of intermediate or surrogate end-point markers that are linked to an increased risk of cancer (Ki-67 [a marker of cell proliferation], epidermal growth factor receptor, p53, Her-2/neu [also known as erbB-2 and ERBB2], globular actin, and abnormal DNA ploidy). Reported P values are two-sided.

RESULTS

Smokers of any one substance or of two or more substances exhibited more alterations than nonsmokers in five to nine of the 10 histopathologic parameters investigated (all P < .05), and they exhibited more molecular abnormalities than nonsmokers. Differences between smokers and nonsmokers were statistically significant (all P < or = .01) for Ki-67, epidermal growth factor receptor, globular actin, and DNA ploidy. There was general agreement between the presence of molecular abnormalities and histopathologic alterations; however, when disagreement occurred, the molecular abnormalities (e.g., Ki-67 and epidermal growth factor receptor) were more frequently altered (all P < or = .01).

CONCLUSIONS

These findings suggest that smoking marijuana and/or cocaine, like tobacco smoking, exerts field cancerization effects on bronchial epithelium, which may place smokers of these substances at increased risk for the subsequent development of lung cancer.

Marijuana. Respiratory tract effects

Daily marijuana smoking has been clearly shown to have adverse effects on pulmonary function and produce respiratory symptomatology (cough, wheeze, and sputum production) similar to that of tobacco smokers. Based on the tobacco experience, decrements in pulmonary function may be predictive of the future development of chronic obstructive pulmonary disease (COPD). However, in the absence of alpha-1-antitrypsin deficiency, the habitual marijuana-only smoker would likely have to smoke 4-5 joints per day for a span of at least 30 yr in order to develop overt manifestations of COPD. The mutagenic/carcinogenic properties of marijuana smoke are also well-established. The potential for induction of laryngeal, oropharyngeal, and possibly bronchogenic carcinoma from marijuana has been documented by several case reports and observational series. Despite this, a relative risk ratio for the development of these tumors has not yet been quantified. Based on a higher frequency of case reports for upper airway cancer compared to bronchogenic carcinoma, marijuana smoking may have a more deleterious effect on the upper respiratory tract. However, this hypothesis remains speculative at best, pending confirmation by longitudinal studies.

Cocaine: pathophysiology and clinical toxicology

PURPOSE

To review the medical complications of cocaine abuse and the mechanisms of action of cocaine that contribute to medical complications.

DATA SOURCES

Pertinent articles identified through a MEDLINE search of the English-language literature from 1985 to 1996 and through a manual search of bibliographies of all identified articles.

STUDY SELECTION

All articles describing complications of cocaine use including case reports, small reported series, and review articles.

DATA SYNTHESIS

A qualitative description of reported complications.

RESULTS

Since the introduction of freebase and crack cocaine, multiple medical complications have been observed, and all major body organ systems have been affected. Cocaine can cause acute strokes, myocardial infarction, cardiac dysrhythmias, pulmonary edema, rhabdomyolysis, and acute renal failure.

CONCLUSION

Adverse reactions to cocaine should be considered in the differential diagnosis of acute ischemic events that occur in young adults. General awareness of the significant complications of cocaine will facilitate early diagnosis and prompt treatment.

Impact of habitual cocaine smoking on the physiologic response to maximum exercise

BACKGROUND

Habitual smoking of alkaloidal cocaine (crack) has been reported to be associated with a number of cardiopulmonary complications that may not be clinically obvious but could potentially interfere with normal physiologic responses to exercise and thus impair maximum exercise performance.

STUDY OBJECTIVE

To evaluate the impact of regular use of cocaine on maximum exercise.

DESIGN

Observational study in crack users and age- and gender-matched control subjects.

SUBJECTS

Thirty-five habitual cocaine smokers (21 male and 14 female) and 29 age-matched sedentary control nonsmokers of cocaine (15 male and 14 female), all of whom were in good general health.

METHODS

In these subjects, we compared physiologic responses to symptom-limited, incremental maximal exercise performed on a cycle ergometer using a ramp protocol. Comparisons were made for men and women separately.

RESULTS

For both men and women, long-term cocaine smokers had a reduced aerobic capacity (maximum oxygen consumption) compared with control nonsmokers but did not show evidence of ventilatory limitation, reduced gas exchange threshold, increased physiologic dead space, or gas exchange abnormality at maximum exercise compared with the healthy control subjects. Although cocaine smokers had reduced maximum heart rates compared with control subjects, the relationship between submaximal heart rate and oxygen uptake was normal, indicating a normal cardiovascular response pattern. However, effort perception was similar between the two groups despite the difference in heart rate at maximum exercise, suggesting the possibility of perceptual dysfunction for effort. Differences in aerobic capacity between the crack users and nonusers could not be explained by differences in physical fitness or altered perception of dyspnea.

CONCLUSION

In the subjects we studied, long-term cocaine smoking was associated with reduced maximum exercise performance, probably due to poor motivation or altered effort perception. No other identifiable physiologic abnormality appeared to limit exercise in the habitual crack users.

Reduction in the bioelectric properties of swine tracheal submucosal gland cells in culture after daily short-term exposure to cocaine

Chronic use of cocaine has been associated with respiratory complications. In this study, we investigated the effects of daily short-term cocaine exposure on epithelial bioelectric properties and chloride secretion in response to secretagogues in primary culture of swine tracheal submucosal gland cells grown on microporous inserts. Cell cultures exposed continuously to cocaine for 24 h or intermittently for 30 min daily for up to 3 consecutive days, resulted in a concentration-dependent reduction in transwell voltage and transepithelial resistance. Cocaine (300 microM) treatment for 24 h decreased the voltage and resistance by 87 and 75%, respectively. The voltage and resistance were also substantially decreased after 3 days of intermittent cocaine (10-30 microM) exposure. Cocaine exposure protocols used here did not enhance lactate dehydrogenase (LDH) release. Chloride secretion was measured as short-circuit current utilizing Ussing chamber methodology. Cocaine exposure did not change the decreases in short-circuit current caused by amiloride (10 microM), but reduced the increases in short-circuit current induced by acetylcholine and isoproterenol. After 3 days of intermittent cocaine (30 microM) exposure, the maximal acetylcholine and isoproterenol responses were reduced by 67 and 71%, respectively. Therefore, cocaine exposure continuously for 24 h or intermittently for 30 min daily for up to 3 days decreased basal transepithelial voltage as well as resistance and reduced the responses to cholinergic and beta-adrenoceptor agonists. These results suggest that alterations in epithelial function can occur even after daily transient cocaine exposure.

Tracheobronchial histopathology in habitual smokers of cocaine, marijuana, and/or tobacco

BACKGROUND

Marijuana and alkaloidal cocaine ("crack") are the two most commonly smoked substances in the United States after tobacco. While regular tobacco smoking has been found to be associated with extensive microscopic alterations in bronchial mucosa, little information is available concerning the effect of crack cocaine and marijuana on tracheobronchial histopathology.

STUDY OBJECTIVE

To determine the relative impact of smoked substances (cocaine, marijuana, and tobacco) alone and in combination on the histopathology of the tracheobronchial mucosa and to assess whether the effects of habitual smoking of two or more substances (cocaine, marijuana, and/or tobacco) are additive.

DESIGN

Observational cohort study.

SUBJECTS

Fifty-three nonsmoking control subjects (NS), 14 current, habitual smokers of crack cocaine only (CS), 40 current, regular smokers of marijuana only (MS), 31 regular smokers of tobacco only (TS), 16 current smokers of both cocaine and marijuana (CMS), 12 current smokers of both cocaine and tobacco (CTS), 44 current smokers of both marijuana and tobacco (MTS), and 31 current smokers of cocaine, marijuana, and tobacco (CMTS).

METHODS

After preliminary screening evaluation, including a detailed respiratory and general health questionnaire and routine pulmonary function studies, subjects underwent fiberoptic bronchoscopy with endobronchial biopsies of the mucosa of the primary carina and randomly selected secondary or tertiary carinae. Biopsy specimens were processed for light microscopy, stained with hematoxylin-eosin or periodic acid-Schiff, and examined to assess epithelial, basement membrane, and submucosal alterations by one or two pathologists who were masked to the smoking status of the subject.

RESULTS

Smokers of cocaine, marijuana, or tobacco alone all exhibited more frequent abnormalities than NS in 10 (CS) or all 11 (MS and TS) of the histopathologic features assessed. For most features, MS and TS showed significantly more frequent alterations than NS (p < or = 0.02), while CS showed significantly more frequent abnormalities than NS in only three features (p<0.05) and nearly significant differences from NS in two additional features (p < or = 0.09). Alterations were noted most frequently in CTS (six features) and MTS (three features), while abnormalities were relatively infrequent in CMS. For 10 features, MTS had more frequent alterations than MS and TS. With a single exception, CMTS did not show more frequent alterations than CTS or MTS.

CONCLUSION

Marijuana and tobacco smoking each produces significant bronchial mucosal histopathology and the effects of marijuana and tobacco appear additive. Cocaine appears to lead to fewer significant bronchial mucosal alterations than marijuana or tobacco when smoked alone and does not add to the changes associated with marijuana. When smoked together with tobacco, however, cocaine appears to augment the bronchial injury caused by tobacco smoking.

Effects of 'crack' cocaine on pulmonary alveolar permeability

BACKGROUND

Lung clearance of 99mTc-labeled diethylenetriamine pentaacetate (DTPA) is a sensitive test of altered alveolar epithelial permeability that has been found to be increased in smokers of tobacco, as well as a small number of healthy smokers of crack cocaine, suggesting the possibility of subclinical crack-related lung injury.

STUDY OBJECTIVE

To evaluate further whether habitual smoking of cocaine alone alters alveolar permeability, whether crack smoking adds to or potentiates the effects of tobacco and/or marijuana, and whether experimental cocaine smoking acutely alters DTPA lung clearance.

DESIGN

Observational cohort study (habitual cocaine smoking) and single-blind crossover study (experimental cocaine administration).

SUBJECTS

Fourteen habitual smokers of cocaine alone (CS), 19 smokers of cocaine and tobacco (CTS), 3 smokers of cocaine and marijuana, 12 smokers of cocaine, tobacco, and marijuana (CMTS), and 5 smokers of marijuana plus tobacco (MTS). Results obtained in the crack-smoking subjects were compared with data previously obtained in 10 nonsmokers (NS), 9 smokers of tobacco alone (TS), 10 smokers of marijuana alone (MS), and 4 additional MTS.

METHODS

Subjects underwent measurements of DTPA radioaerosol lung clearance after refraining from marijuana and/or cocaine for > 12 h and from tobacco for >2 h. Ten of the 48 crack users were tested on two days 1 to 2 weeks apart within 2 h of experimental smoking of three physiologically active or inactive doses (total 98.8+/-15.5 or 8.5+/-2.5 mg, respectively) of cocaine base. Lung clearance half-times (T1/2) were computed from time-activity curves for each lung.

RESULTS

T1/2 values for each lung in CS and MS were comparable to those of NS, while TS, MTS, CTS, and CMTS had significantly shorter clearance rates than NS (p<0.01; three-way analysis of variance). No additive or interactive effects on T1/2 were noted among tobacco, cocaine, and/or marijuana. No acute effect of experimental cocaine smoking on T1/2 was noted.

CONCLUSION

Whereas regular smoking of tobacco alone or with other substances increases alveolar epithelial permeability, habitual smoking of cocaine and/or marijuana has no measurable effect on alveolar permeability in the absence of tobacco nor any additive effect to that of tobacco alone.