Utilization of hair analysis for therapeutic drug monitoring with a special reference to ofloxacin and to nicotine

The Effect of Passive Smoking on Early Clinical Outcomes After Total Knee Arthroplasty Among Female Patients

PURPOSE

The aim of this study was to assess whether passive smoking affects clinical outcomes among female patients with knee osteoarthritis after being treated with total knee arthroplasty (TKA).

METHODS

The study prospectively enrolled 216 female patients who did not smoke and those patients were classified into three groups in terms of the severity of exposure to environmental tobacco smoke. A three-month follow-up was conducted to assess the physical and mental outcomes between the three groups. The physical outcomes were evaluated by the visual analogue score (VAS), range of motion (ROM), hospital for special surgery (HSS) knee score, and postoperative complications. The mental outcomes were assessed by the anxiety and depression scale (HADS) and medical outcome study short form 36 (SF-36). Subgroup analysis of patients with and without surgical site infection (SSI) was also calculated.

RESULTS

Baseline characteristics were similarly distributed between the three groups (P>0.05). Patients in the heavy passive smoking group had a higher VAS and a lower ROM score as compared with patients in the no and mild passive smoking group at discharge (P<0.01), 1 month (P<0.01), and 3 months (P<0.01) after surgery. Patients in the heavy passive smoking group also had a higher rate of HADS more than 8 at postoperative 1 month (P=0.01) and 3 months (P=0.03) and lower SF-36 summary (P<0.01) and HSS score (P<0.01) at postoperative 3 months. Forty-five postoperative complication events were observed during follow-up. Patients in the heavy passive smoking group (8.51%) had the highest SSI rate, followed by patients in the mild (1.82%) and no passive smoking group (0.88%) at discharge (P=0.02) and postoperative 1 month (P=0.03).

CONCLUSION

Passive smoking negatively affects TKA among female patients. It may trigger poor pain and functional outcomes, aggravate depression and anxiety, and deteriorate quality of life after discharge from hospital. Avoiding exposure to smoking environment may be beneficial among TKA female patients before and after surgery.

Questionnaire-Based Environmental Tobacco Smoke Exposure and Hair Nicotine Levels in 6-month-old Infants: A Validation Study in Indonesia

Objectives. Using hair nicotine as the gold standard, this study aimed to establish cutoff points and validate the questionnaire-based environmental tobacco smoke (ETS) exposure and ETS statuses of Indonesian infants. Methods. A cross-sectional study design was conducted among families who were participants of the Peer Health Cohort Study in Jakarta, Indonesia. Households with 6-month-old infants joined this study. The presence and amount of ETS exposure were assessed by both questionnaire and hair sampling for nicotine determination. Head hair samples were collected from 102 infants and measured by optimized gas chromatography-mass spectrometry (GC/MS). Infants were grouped as ETS-exposed if they lived with at least 1 smoker at home. We used the receiver operating characteristic (ROC) curve to assess the sensitivity and specificity of cutoff values of hair nicotine. Results. There were 78 (76.5%) infants exposed to ETS based on the questionnaire. The nicotine concentrations in hair were significantly higher in infants with ETS exposure than in those without ETS exposure (P < .001). The area under the curve for nicotine was 0.774. A hair nicotine cutoff value of 2.37 ng/mg, with a sensitivity of 67.95% and specificity of 83.33%, was identified as the optimal cutoff value for separating exposed from non-exposed to ETS in infants. Conclusion. The hair nicotine value of infants aged 6 months is useful in confirming the questionnaire on smoking in the household and exposure to ETS. Moreover, it also could be used to distinguish ETS-exposed from non-ETS-exposed infants.

Evaluation of hair cotinine and toxic metal levels in children who were exposed to tobacco smoke

Tobacco or tobacco products (TTP) are harmful because they contain nicotine and some heavy metals. In this study, it was aimed to evaluate whether the responses of parents to questionnaires were compatible with the hair cotinine levels of their children, and to investigate whether exposure to environmental tobacco smoke (ETS) and living conditions increased the levels of cotinine, lead (Pb), arsenic (As), and cadmium (Cd) in the hair samples of the children. Questionnaires were administered to the parents questioning household consumption of TTP and living conditions. Children were grouped as "exposed to ETS" (E-ETS) and "not exposed to ETS" (NE-ETS). This grouping was performed through a questionnaire-based evaluation, and a hair cotinine cut-off value-based evaluation. According to the questionnaire-based evaluation, there were no significant differences in hair Pb, As, and Cd levels between the groups (P-values: .337, .994, and .825, respectively). The hair cotinine of the E-ETS group was higher (0.24 ± 0.21 vs 0.22 ± 0.15 ng/mg), but the difference was not statistically significant (P = .317). According to the cotinine evaluation, cotinine, Pb, and As levels were statistically higher in the E-ETS group (P < .001, <.001, and .036, respectively), but there was no statistical difference between the groups in terms of Cd levels (P = .238). Our results showed that exposure to ETS increased the levels of cotinine, Pb, and As in the hair samples of children, and the questionnaire responses of the parents about their smoking habits might not be compatible with the hair cotinine levels of the children.

Comparison of plasma, saliva, and hair lamotrigine concentrations

BACKGROUND

In some clinical situations (pregnancy, aging, drug resistance, toxicity), measurements of lamotrigine plasma levels may be reliable. Limited studies indicate that saliva and hair could be alternative sources for monitoring lamotrigine therapy. The drug content in hair can also be used to assess the history of drug therapy and to ascertain long-term patient compliance. The aims of this study were to 1) determine the correlations among plasma, saliva, and hair lamotrigine concentrations, 2) evaluate saliva as an alternative matrix for monitoring drug levels and 3) evaluate hair as a source of information on adherence to antiepileptic treatment and on the correlation of hair concentrations with clinical outcomes in patients with epilepsy.

METHODS

Plasma, saliva, and hair lamotrigine concentrations were measured by liquid chromatography-tandem mass spectrometry in positive ionization mode. The study group (n = 85) was recruited among the epileptic patients at the Institute of Psychiatry and Neurology, Warsaw, Poland.

RESULTS

Plasma concentrations were not influenced by sex, age, or the concomitant use of other antiepileptic drugs. Lamotrigine saliva and plasma concentrations were strongly correlated (r = 0.82, p < 0.001). Lamotrigine hair concentrations were correlated with the plasma concentrations (r = 0.53, p < 0.001) and daily dose in mg/kg (r = 0.23, p = 0.024). The analysis revealed no significant correlation between lamotrigine hair levels and the number of seizures in the previous 3 months (r = -0.1, p > 0.05).

CONCLUSIONS

The lamotrigine saliva concentration is strongly correlated with its plasma level, and saliva can be used as an alternative matrix to plasma for monitoring. Lamotrigine can also be successfully measured in hair, and the drug levels in hair tend to be correlated with the levels in plasma. However, lamotrigine levels in hair may not correspond to clinical outcomes (i.e., seizure episodes).

Differential correlations between maternal hair levels of tobacco and alcohol with fetal growth restriction clinical subtypes

Maternal exposure to tobacco and alcohol is a known cause, among others, for fetal growth restriction (FGR). Clinically, FGR can be subclassified into two forms: intrauterine growth restriction (IUGR) and small for gestational age (SGA), based on the severity of the growth retardation, and abnormal uterine artery Doppler or cerebro-placental ratio. This study aimed at investigating any differential correlation between maternal exposures to these toxins with the two clinical forms of FGR. Therefore, a case-control study was conducted in Barcelona, Spain. Sixty-four FGR subjects, who were further subclassified into IUGR (n = 36) and SGA (n = 28), and 89 subjects matched appropriate-for-gestational age (AGA), were included. The levels of nicotine (NIC) and ethyl glucuronide (EtG), biomarkers of tobacco and alcohol exposure, respectively, were assessed in the maternal hair in the third trimester. Our analysis showed 65% of the pregnant women consumed alcohol, 25% smoked, and 19% did both. The odds ratios (ORs) of IUGR were 21 times versus 14 times for being SGA with maternal heavy smoking, while with alcohol consumption the ORs for IUGR were 22 times versus 37 times for the SGA group. The differential correlations between these toxins with the two subtypes of FGR suggest different mechanisms influencing fetal weight. Our alarming data of alcohol consumption during pregnancy should be considered for further confirmation among Spanish women.

Secondhand Smoke Exposure and Validity of Self-Report in Low-Income Women and Children in India

BACKGROUND

There is limited validation of self-reported measures for secondhand smoke (SHS) exposure in low- and middle-income countries. We evaluated the validity of standard self-reported measures among women and children in urban India.

METHODS

Structured questionnaires were administered, and household air and hair samples were analyzed for nicotine concentration.

RESULTS

In total, 141 households of 70 child and 71 adult participants were included. Air nicotine was detected in 72 (51%) homes, and 35 (75%) child and 12 (56%) adult participants had detectable hair nicotine. Correlation between air and hair nicotine was significant in children (r = 0.5; P = .0002) but not in adults (r = -0.1; P = .57). Poor correlation was found between self-reported measures of exposure and both air and hair nicotine. No questions were significantly correlated with hair nicotine, and the highest-magnitude correlation with air nicotine was for how often someone smoked inside for adults (r = 0.4; P = .10) and for home preparation of mishri (a smokeless tobacco product prepared for consumption by roasting) for children (r = 0.4; P = .39). The highest value for sensitivity by using air nicotine as the gold standard was for whether people smelled other families preparing mishri (47%; 95% confidence interval: 31-62) and prepared mishri in their own homes (50%; 95% confidence interval: 19-81).

CONCLUSIONS

These results raise caution in using or evaluating self-reported SHS exposure in these communities. More appropriate questions for this population are needed, including mishri preparation as a source of SHS exposure.

Utility and cutoff value of hair nicotine as a biomarker of long-term tobacco smoke exposure, compared to salivary cotinine

While hair samples are easier to collect and less expensive to store and transport than biological fluids, and hair nicotine characterizes tobacco exposure over a longer time period than blood or urine cotinine, information on its utility, compared with salivary cotinine, is still limited. We conducted a cross-sectional study with 289 participants (107 active smokers, 105 passive smokers with self-reported secondhand smoke (SHS) exposure, and 77 non-smokers with no SHS exposure) in Baltimore (Maryland, USA). A subset of the study participants (n = 52) were followed longitudinally over a two-month interval. Median baseline hair nicotine concentrations for active, passive and non-smokers were 16.2, 0.36, and 0.23 ng/mg, respectively, while those for salivary cotinine were 181.0, 0.27, and 0.27 ng/mL, respectively. Hair nicotine concentrations for 10% of passive or non-smokers were higher than the 25th percentile value for active smokers while all corresponding salivary cotinine concentrations for them were lower than the value for active smokers. This study showed that hair nicotine concentration values could be used to distinguish active or heavy passive adult smokers from non-SHS exposed non-smokers. Our results indicate that hair nicotine is a useful biomarker for the assessment of long-term exposure to tobacco smoke.

Detection of Leishmania infantum kinetoplast minicircle DNA by Real Time PCR in hair of dogs with leishmaniosis

It is known that hair can accumulate environmental toxics and excrete foreign chemical or biological substances. In this context, we hypothesized that foreign DNA could be found in the hair of an infected organism, and thus, be detected by Real Time PCR in the hair of Leishmania infantum naturally infected dogs. A population of 28 dogs living in Leishmania endemic areas was divided into two groups: A (13 Leishmania infected dogs) and B (15 healthy dogs). Blood, lymph node and ear hair samples from all of them were tested for the presence of parasite kinetoplast DNA (kDNA). For the same purpose, hair of several body areas and hair sections of two infected dogs were also analyzed. Epidermal keratinocytes from an infected animal were also analyzed for reactivity against Leishmania antigens by ELISA and for the presence of kDNA. Regarding to dogs from group A, parasite kDNA was detected in the 100% of lymph node samples. The sensitivity of Real Time PCR in ear hair was similar to that obtained in blood (9 positive out of 13 versus 8 positive out of 13, respectively). Moreover, the presence of L. infantum kDNA was also detected in the hair of all the analyzed body zones, in all hair sections and in epidermal keratinocytes. In infected dogs, parasite kDNA could be detected and quantified from just one single hair, whereas it was not detected in any of the samples of the healthy dogs. This work describes a new method for a reliable and non-invasive diagnosis of canine leishmaniosis using hair samples of infected animals. The data presented also provide some insights for the understanding of the physiology of keratinocytes and the role of hair as a specialized tissue in the kidnapping and removal of foreign DNA.

Collection of biological samples in forensic toxicology

Forensic toxicology is the study and practice of the application of toxicology to the purposes of the law. The relevance of any finding is determined, in the first instance, by the nature and integrity of the specimen(s) submitted for analysis. This means that there are several specific challenges to select and collect specimens for ante-mortem and post-mortem toxicology investigation. Post-mortem specimens may be numerous and can endow some special difficulties compared to clinical specimens, namely those resulting from autolytic and putrefactive changes. Storage stability is also an important issue to be considered during the pre-analytic phase, since its consideration should facilitate the assessment of sample quality and the analytical result obtained from that sample. The knowledge on degradation mechanisms and methods to increase storage stability may enable the forensic toxicologist to circumvent possible difficulties. Therefore, advantages and limitations of specimen preservation procedures are thoroughfully discussed in this review. Presently, harmonized protocols for sampling in suspected intoxications would have obvious utility. In the present article an overview is given on sampling procedures for routinely collected specimens as well as on alternative specimens that may provide additional information on the route and timing of exposure to a specific xenobiotic. Last, but not least, a discussion on possible bias that can influence the interpretation of toxicological results is provided. This comprehensive review article is intented as a significant help for forensic toxicologists to accomplish their frequently overwhelming mission.

Determination of hair nicotine by gas chromatography-mass spectrometry

Hair nicotine is a known biomarker for monitoring long-term environmental tobacco smoke (ETS) exposure and smoking status. In general, hair nicotine assay involves alkaline digestion, extraction and instrumental analysis. The gas chromatography-mass spectrometry (GC-MS) assay currently developed has shown to be of high throughput with average approximately 100 hair samples being extracted and analyzed per day. This was achieved through simplified extraction procedure and shortened GC analysis time. The extraction was improved by using small volume (0.4 mL) of organic solvent that does not require further evaporation and salting steps prior to GC-MS analysis. Furthermore, the amount of hair utilized in the extraction was very little (5 mg) while the sensitivity and selectivity of the assay is equal, if not better than other established methods. The linearity of the assay (r(2)>0.995), limit of quantitation (0.04 ng/mg hair), within- and between-assays accuracies and precisions (<11.4%) and mean recovery (92.6%) were within the acceptable range.

Determination of Opioid Analgesics in Hair Samples Using Liquid Chromatography/Tandem Mass Spectrometry and Application to Patients Under Palliative Care

Hair testing procedures allow a cumulative reflection of long-term drug abuse and are useful as a test for compliance in clinical toxicology. In the present study, liquid chromatography coupled with tandem mass spectrometry was used to determine analgesic opioid drugs in hair samples. The procedure used a simple methanolic extraction, and the evaporated extract was analyzed directly. A selective and sensitive procedure for the simultaneous determination of bisnortilidine, nortilidine, tilidine, buprenorphine, codeine, oxycodone, fentanyl, norfentanyl, hydromorphone, morphine, normorphine, oxymorphone, methadone, piritramide, and tramadol was developed and fully validated. The method fulfilled validation criteria and was shown to be sensitive, with limits of detection ranging from 0.008 to 0.017 ng/mg hair matrix, and precision ranging between 3.1% and 14.9 %. The applicability of the method was shown by analysis of authentic hair samples from patients receiving opioids for the treatment of cancer pain (eg, fentanyl was detected in concentrations up to 0.292 ng/mg, tramadol in concentrations up to 0.612 ng/mg of hair of 1 patient). Hair analysis was shown to be a complementary and useful tool in monitoring the drug-taking behavior of patients consuming opioid analgesics for the treatment of pain. In self-reports and medical records especially, the ingestion of tramadol and methadone was found to be dramatically underreported. In summary, hair analyses gave important additional information for the medical treatment of patients, the results often coming as a surprise to even the attending physicians.

The California Tobacco Control Program's effect on adult smokers: (2) Daily cigarette consumption levels

OBJECTIVE

To investigate the association of the California Comprehensive Tobacco Control Program with self-reported population trends of cigarette consumption during 1992-2002.

SETTING AND PARTICIPANTS

Participants were non-Hispanic white daily smokers (aged 20-64 years, n = 24 317) from the Tobacco Use Supplements to the Current Population Survey (1992-2002). We compared age-specific trends in consumption among daily smokers in three groups of states with differing tobacco control initiatives: California (CA; high cigarette price/comprehensive programme), New York and New Jersey (high cigarette price/no comprehensive programme), and tobacco-growing states (TGS; low cigarette price/no comprehensive programme).

RESULTS

There was a general decline in cigarette consumption across all age groups in each category of states between 1992 and 2002, except the oldest age group in the TGS. The largest annual decline in the average number of cigarettes per day was observed among daily smokers in CA who were aged > or = 35 years (-0.41 cigarettes/day/year (95% CI -0.52 to -0.3)). This rate was significantly higher than the -0.22 cigarettes/day/year (95% CI -0.3 to -0.16; p<0.02) observed in same-age daily smokers from New York and New Jersey, and significantly higher than the rate in same-age daily smokers from the TGS (-0.15 cigarettes/day/year (95% CI -0.22 to -0.08; p<0.002)). There were no significant differences across state groups in the decline observed in daily smokers aged 20-34 years. In 2002, only 12% of daily smokers in CA smoked more than a pack per day, which was significantly lower than the 17% in New York and New Jersey, which again was significantly lower than the 25% in the TGS.

CONCLUSIONS

The California Tobacco Control Program was associated with significant declines in cigarette consumption among daily smokers aged > or = 35 years of age, which in turn should lead to declines in tobacco-related health effects. The decline in consumption among young adult smokers was a national trend.

Turkish coffeehouse kahvehane is an important tobacco smoke exposure area in Turkey

This study was undertaken to investigate the extent of environmental tobacco smoke (ETS) exposure in coffeehouses, as these are commonly frequented public places in Turkey. From 86 coffeehouses in the 3 districts, 59 coffeehouse workers and 35 hospital staff members (as a control group) were evaluated. Participants answered a questionnaire about demographics, working characteristics, smoking behavior, and ETS exposure during their daily life lives. The amount of nicotine in hair was determined by using gas chromatography/mass spectrometry (GC/MS). The mean hair nicotine level of the nonsmoker and smoker coffeehouse workers were 23.2 +/- 12.3 microg/g and 62.5 +/- 49.8 microg/g, respectively. Among the hospital staff, mean hair nicotine levels were 4.5 +/- 6 microg/g in nonsmokers and 30.6 +/- 14 microg/g in smokers. Working in coffeehouses has a marked effect on hair nicotine levels and potential adverse health effects.

Detection of enrofloxacin and its metabolite ciprofloxacin in equine hair

Hair analysis to detect drug administration has not been studied extensively in horses. This study aimed to (a) develop an analytical method for enrofloxacin and its metabolite ciprofloxacin in mane and tail hair, (b) relate measured values to doses, routes of administration, hair colour, and (c) demonstrate long-term detectability. Samples were extracted in trifluoroacetic acid at 70 degrees C. Extracts were cleaned-up by solid-phase extraction and analysed by high-performance liquid chromatography with UV-diode array detection. Analyte recoveries were > 87%. Horses were sampled after therapeutic enrofloxacin administration either orally at 7.5 mg/kg daily for 3-13 days or twice daily for 10-14 days (Group 1, n=7) or intravenously at 5.0 mg/kg daily for 12 and 15 days (Group 2, n=2). Enrofloxacin and ciprofloxacin were detected at concentrations up to 452 and 19 ng/mg, respectively, up to 10 months post-treatment. In vitro, enrofloxacin and ciprofloxacin were extensively bound to melanin (> 96%) and in vivo, their uptake was 40-fold greater in black than white hair. Enrofloxacin and ciprofloxacin concentrations correlated to enrofloxacin dose (r2=0.777 and r2=0.769). Enrofloxacin:ciprofloxacin ratios were 21:1 and 13:1 following intravenous and oral administration, respectively. Longitudinal analyte distributions correlated to treatment-sampling interval.

Clinical considerations in study designs that use cotinine as a biomarker

Subjects enrolled in studies are not always screened for routine habits such as smoking. Personal history is not always reliable and therefore an objective biomarker is necessary to screen for smokers. The objectives of this article were to review the metabolism of nicotine and other metabolic considerations associated with smoking; to review some of the routine methods used to assess exposure to nicotine-containing products; to revisit cotinine breakpoints utilized to distinguish smokers from non-smokers during screening for clinical trials; to assess the utility of screening questions regarding smoking practices; and to recommend standards for clinical pharmacology studies. The results indicated that cotinine levels serve as a useful biomarker of tobacco exposure; racial issues may be clinically relevant in determining smoking status; cessation of smoking should occur at least 14 days prior to the start of the study; adverse effects from nicotine withdrawal such as craving, hunger and weight gain may persist for more than 6 months; potential metabolic interactions via cytochrome P2A6 and P1A2 need to be considered when designing a study; and the use of a single calibrator as a breakpoint is acceptable if a categorical outcome such as 'smoker' versus 'non-smoker' is desired. Nicotine from food products is not expected to impact assay sensitivity or to be clinically relevant; a serum cotinine concentration of 10 ng ml(-1) be employed as a breakpoint for non-smokers versus smokers; other non-invasive alternatives are collection of urine, saliva, or hair (with suggested breakpoints of 200 ng ml(-1), 5 ng ml(-1) and 0.3 ng mg(-1), respectively; screening questions be accompanied by testing for cotinine; and the inclusion of smokers in studies should be considered once the impact of smoking on the targeted population is understood.

Hair as a biomarker for exposure to tobacco smoke

This article provides an overview of the hair nicotine biomarker for assessment of exposure to tobacco smoke, with emphasis on environmental tobacco smoke (ETS). Measurement of nicotine in hair can be an informative tool for research looking at ETS and related illnesses. There are still unresolved issues in relation to this biomarker such as influence of hair treatment, hair colour, and growth rate on nicotine levels in hair, which need to be addressed in order to further refine this biomarker for exposure assessment. Nevertheless, hair nicotine promises to be a valid and reliable measure of longer term exposure that can be readily applied in epidemiological studies of exposure to tobacco smoke, and more specifically ETS, and its risk to health.

Self-discontinuation of antiepileptic medication in pregnancy: detection by hair analysis

PURPOSE

Concerns over teratogenicity of antiepileptic drugs (AEDs) during pregnancy must be balanced against the risks of seizures to the mother and developing fetus. Pharmacokinetic changes and vomiting may alter drug levels, but more important may be the patient's decision to stop medication before or during pregnancy. Compliance assessment traditionally relies either on self-reporting or on AED plasma level monitoring; neither provides reliable information on drug-taking behaviour over an extended interval (e.g., before, during, and after pregnancy).

METHODS

We have used hair analysis to assess AED-taking behavior in pregnant women compared with nonpregnant female controls. Twenty-six pregnant women [mean age, 27.5 +/- 6.7 (SD) years] and 13 nonpregnant female epilepsy outpatients (mean age, 31.9 +/- 8.3 years) were studied. Carbamazepine (CBZ) or lamotrigine (LTG) concentrations were measured in 1-cm hair segments, and the within-subject variance in segmental hair concentrations of these drugs was calculated for each group. The variances of each group were then compared by using a variance ratio test.

RESULTS

The variance of AED concentration in hair differed significantly between the pregnant and nonpregnant groups [variance ratio, 1.59 (p < 0.01)]. Four (15%) of the 26 pregnant patients had little or no AED in their proximal hair segments compared with more distal segments, apparently having discontinued their medication during pregnancy. Only one of these later disclosed having stopped her medication. One pregnant woman whose hair profile was similar to controls died suddenly at 30 weeks of gestation.

CONCLUSIONS

This study confirms the perception that pregnant women with epilepsy frequently stop or greatly reduce their prescribed medication, usually without reference or acknowledgement to their clinician.

Relation between dosage of carbamazepine and concentration in hair and plasma samples from a compliant inpatient epileptic population

Compliance is a problem in all areas of therapeutic medicine. Methods for its assessment are classified as either indirect or direct. Indirect assessment is based on criteria such as pill counts, questionnaires, and self-reporting; direct methods involve the analytic measurement of the drugs in biologic fluids such as plasma or urine. Drugs taken either therapeutically or recreationally become incorporated into hair. This prospective study investigated the relation between the daily intake of the antiepileptic drug carbamazepine and both its trough plasma and hair concentrations in a highly supervised inpatient population of patients with epilepsy during a period of 6 months. Results showed that although there was a significant variation between patients resulting from the substantial range in the daily intake of carbamazepine (800-2400 mg/day), the intrapatient variation in both trough plasma and hair concentrations during the 6-month period were not significantly different. The mean intrapatient percentage coefficient of variation in total plasma and hair concentrations of carbamazepine was 11.5 +/- 4.7 and 15.0 +/- 5.2, respectively, both of which were independent of the daily dosage. This relatively small intrapatient variation in hair concentration over time and its close relation to the plasma concentration suggests that hair analysis may be a complementary and useful technique in monitoring drug-taking behavior.

Differentiation of hair growth cycle from scalp hair roots for the diagnosis of glucose-6-phosphate dehydrogenase deficiency in neonates

Hair analysis can be used as a screening tool in the diagnosis of genetic diseases. The scalp hair roots of 67 normal neonates and 39 neonates with glucose-6-phosphate dehydrogenase (G6PD) deficiency were analysed using Fourier transform infrared (FT-IR) microspectroscopy to differentiate the stages of the hair growth cycle and to diagnose the genetic disorder on the basis of spectral differences. We have demonstrated that FT-IR microspectroscopy is a rapid and effective noninvasive diagnostic method to differentiate scalp hair roots of normal neonates into the anagen, catagen or telogen phases of the hair growth cycle, using IR spectral differences within the 3000-2800 cm(-1) region and the IR peak area ratio of 2854 cm(-1)/2873 cm(-1) or 1084 cm(-1)/amide II band (p<0.001). Moreover, G6PD-deficient neonates could be accurately diagnosed from telogen phase hair roots owing to significant differences in IR peak area ratios of 2854 cm(-1)/2873(-1) or 1084 cm(-1)/amide II band compared to normal values in healthy neonates. The result suggests that the application of FT-IR microspectroscopy may be capable not only of differentiating the hair growth cycle into anagen, categen or telogen phases but also of detecting G6PD deficiency. Hair root analysis promises to be a useful complement to serum and urine analysis in the diagnosis of genetic diseases.

Analysis of fluoroquinolones in biological fluids by high-performance liquid chromatography

High-performance liquid chromatographic methods for the analysis of fluoroquinolones in biological fluids are reviewed. In particular, sample preparation and handling procedures, chromatographic conditions, and detection methods are discussed. A summary of published high-performance liquid chromatographic assays for individual fluoroquinolones is included.

Clinical outcome of smoking-cessation trial of nicotine chewing gum evaluated by analysis of nicotine in hair

The axial distribution of nicotine along the hair shafts was examined in 21 subjects enrolled in a placebo-controlled, double-blind trial of nicotine chewing gum (Nicorette) for validating their self-reported smoking behavior and their physicians' assessments. Hair samples obtained from the subjects once during the 3-month follow-up period (n = 10 for placebo and n = 11 for Nicorette ad libitum) were analyzed for the cm x cm distribution of nicotine along the hair shafts. Hair analysis results were compared with the monthly self-reports and with the plasma concentrations of thiocyanate (SCN-) measured at 1-month intervals. A gradual decrease in nicotine content along the hair shafts generally corresponded to the decrease in self-reported number of cigarettes smoked daily by the subjects who reported that they abstained from smoking or decreased the number of daily cigarettes in placebo and nicotine chewing gum groups. Because nicotine may dissociate slowly from hair follicle cells, nicotine in the hair did not mark a sudden decrease or cessation of smoking and, therefore, hair analysis tended to underestimate the real decrease of smoking. However, physician assessment seemed to depend solely on self-reporting because the time profile of changes in serum SCN- concentration did not correspond necessarily to the changes in the self-reported number of cigarettes used daily.

The axial distribution of nicotine content along hair shaft as an indicator of changes in smoking behaviour: evaluation in a smoking-cessation programme with or without the aid of nicotine chewing gum

1. Hair samples were obtained from subjects at the end of a 6 month smoking-cessation programme carried out with (n = 16) or without (n = 10) the aid of nicotine chewing gum. The axial distribution of nicotine along the hair shaft was determined and compared both with the self-report of smoking behavior and with the concentration of carbon monoxide (CO) in expired air measured at 1 month intervals. 2. A gradual decrease in nicotine content along the hair shaft corresponded to the decrease in self-reported number of cigarettes smoked daily in both the nicotine chewing-gum treated and untreated subjects and with the clinical assessment of abstinence. 3. There was reasonable agreement between the CO content of expired air, the self-reported number of cigarettes smoked daily and the axial distribution of nicotine in 22 of 26 subjects. In the other four subjects there was an apparent disagreement between the CO content of expired air and the other parameters. 4. This study showed that, as a routine marker of smoking status, hair analysis may be preferable to repeated CO measurements since only a single sample at the end of an abstinence programme might be sufficient. However, one problem is that nicotine may dissociate slowly from melanin to limit the ability to mark a sudden cessation of smoking. Also, some nicotine in hair might be attributable to nicotine adsorbed to the outside of hair.