Drug treatment in an ageing population: practical implications

Adrenal crises in older patients

Adrenal crises are severe manifestations of adrenal insufficiency that result in hospital admission and incur a risk of cardiovascular events, acute renal injury, and death. Evidence from population-based studies indicate that adults older than 60 years have the highest adrenal insufficiency incidence, contribute to the highest number of adrenal crises, and have the highest age-specific incidence of adrenal crisis, which doubles between the age groups of 60-69 years and 80 years or older. Older patients might be more susceptible to adrenal crises because of a higher prevalence of comorbidities and a consequently higher risk of acute illness. This susceptibility might be compounded by shortfalls in the implementation of prevention strategies for adrenal crisis, because of individual and social factors that increase with age. Although little research has focused on adrenal crisis prevention in older patients, it seems logical that a timely diagnosis of adrenal insufficiency and the use of consensus driven adrenal crisis prevention and attenuation strategies might reduce adrenal crises in patients older than 60 years old.

Prevalence of polypharmacy and the association with non-communicable diseases in Qatari elderly patients attending primary healthcare centers: A cross-sectional study

BACKGROUND

Polypharmacy has become a global public health concern particularly in the elderly population. The elderly population is the most susceptible to the negative effects of polypharmacy due to their altered pharmacokinetics and decreased drug clearance. Therefore, polypharmacy can lead to poor health status and higher rates of morbidity and mortality.

OBJECTIVE

The objective of this study was to determine the prevalence of polypharmacy (≥ 5 drugs) and its association with non-communicable diseases (NCDs) in elderly (≥65 years) Qatari patients attending Primary Healthcare (PHC) centers in Qatar.

METHODS

A retrospective cross-sectional analysis was conducted using the Electronic Medical Record (EMR) database of all PHC centers in Qatar for six months (April-September 2017).

RESULTS

Out of 5639 patients screened, 75.5% (95% CI: 74.3-76.6) were exposed to polypharmacy. Females were 1.18 times more likely to have polypharmacy compared to males (95% CI: 1.03-1.34). The multivariate analysis identified having hypertension (AOR 1.71; 95% CI: 1.38-2.13), diabetes (AOR 2.38; 95% CI: 1.97-2.87), dyslipidemia (AOR 1.29; 95% CI: 1.06-1.56), cardiovascular disease (AOR 1.56; 95% CI: 1.25-1.95) and asthma (AOR 1.39; 95% CI: 1.13-1.72) to be independent parameters associated with polypharmacy. Also, the Body Mass Index (BMI) and number of NCDs were found to be significant independent parameters associated with polypharmacy.

CONCLUSIONS

The prevalence of polypharmacy among Qatari elderly attending PHC Centers is very high. Our findings confirm the strong relationship between polypharmacy and BMI, and certain NCDs. Healthcare professionals should be educated about the magnitude of polypharmacy, its negative effects, and its associated factors. Best practice guidelines should be developed for improved medical practice in the prescription of medications for such a vulnerable population.

Challenges and innovations of drug delivery in older age

Both drug delivery performance and various age-related physical, mental and physiological changes can affect drug effectiveness and safety in elderly patients. The many drug delivery systems developed over the years include recent novel transdermal, nasal, pulmonary and orally disintegrating tablets that provide consistent, precise, timely and more targeted drug delivery. Certain drug delivery systems may be associated with suboptimal outcomes in the elderly because of the nature of drug present, a lack of appreciation of the impact of age-related changes in drug absorption, distribution and clearance, the limited availability of pharmacokinetic, safety and clinical data. Polypharmacy, patient morbidity and poor adherence can also contribute to sub-optimal drug delivery systems outcomes in the elderly. The development of drug delivery systems for the elderly is a poorly realised opportunity, with each system having specific advantages and limitations. A key challenge is to provide the innovation that best meets the specific physiological, psychological and multiple drug requirements of individual elderly patients.

Statin drug interactions and related adverse reactions: an update

INTRODUCTION

Statins reduce the risk of cardiovascular morbidity and mortality in patients with or at risk for cardiovascular disease and their use is expanding, especially in elderly. Statins are prescribed on a long-term basis and may undergo drug-drug interactions (DDIs) with other drugs. Statins have different safety and tolerability, and this might affect the possibility of DDIs with other cardiovascular drugs, increasing the risk of statin-associated myopathy and hepatotoxicity. Polypharmacy and pharmacogenetic variability are potential causes of statin DDIs. Thus, the safety and adverse effects of statins, particularly in patients receiving multiple medications at risk of DDIs, are a matter of special concern.

AREAS COVERED

The purpose of this manuscript is to give an update on the potential statin DDIs and related adverse drug reactions (myopathy and hepatotoxicity), with special considerations on polypharmacy in elderly population, HIV patients, cardiovascular drugs and liver toxicities. The potential DDIs among statins and monoclonal antibodies including the recently approved PCSK9 inhibitors are also extensively discussed in the present review.

EXPERT OPINION

A better understanding of the incidence and clinical significance of statin DDIs will help physicians in fine-tuning the lipid-lowering therapeutic interventions thus providing their patients with an evidence-based, safe and cost-effective clinical support.

Management of Older Inpatients Who Refuse Nonpsychiatric Medication Within Birmingham and Solihull Mental Health NHS Foundation Trust: Audit

The effects of poor medication compliance are well documented and include increased morbidity, early mortality, and financial costs to the society. According to national guidelines, when a competent patient refuses medication, the doctor on duty has a responsibility to ensure the patient understands their proposed course of action. The aims of this audit were to evaluate whether this consultation was taking place within older in-patient units across Birmingham and Solihull Mental Health NHS Foundation Trust when patients refuse nonpsychiatric medicines. Poor compliance was defined as more than five refusals of a nonpsychiatric medication over a 4-week period. A discussion with the duty doctor occurred in 75% of cases (27/36), which resulted in a change in prescription or compliance in 59% (16/27 patients). After patient refusal of medication, a consultation with the duty doctor is likely to improve compliance and uncover salient issues particularly in regards to capacity and drug suitability.

The inability of older adults to recall their drugs and medical conditions

BACKGROUND/OBJECTIVES

Previous research has shown that many older adults without known cognitive impairment are unable to recall basic knowledge about their medical history. We sought to determine whether older adult patients in our own clinic population were able to recall their drug regimens and medical conditions from memory.

METHODS

Patients aged 65 years or older with no known cognitive impairment, dementia, or memory loss who were presenting for routine outpatient follow-up in our medical school neurology and general medicine clinics were recruited. Each patient was asked to recall the number and names of their presently prescribed drugs and their associated medical conditions. Each patient was also administered a Mini-Mental State Examination (MMSE) cognitive screening test (range 0-30).

RESULTS

Most patients were unable to recall their drug regimens or their medical conditions. Of 99 patients taking drugs, only 22% correctly named their drugs from memory, and only 34% correctly named their medical conditions associated with the drugs. Fewer than half (49%) correctly recalled the number of drugs they were taking. Poor recall performance was evident even in high-cognitive (MMSE>27) patients.

CONCLUSION

The accuracy of recall memory in older adults regarding their drugs and medical conditions may be poor, which has important implications towards medication reconciliation within meaningful-use doctrine. Clinicians treating older adults should be very cautious before relying on their patients' memories for accurate recall of their medical conditions, their drug regimens, and even the number of drugs they are taking.

Polypharmacy in the elderly

Polypharmacy is the use of several concurrent medications by one individual. It is an increasingly common phenomenon in an ageing population with multiple morbidities, and can often be a challenge for the GP. When used appropriately, medication can prolong life and aid symptom control. When medications are used unnecessarily, polypharmacy can have adverse effects, particularly on elderly patients. This article aims to help the GP manage patients on multiple medications, be aware of potential problems this may cause, and give guidance on medication reviews.

Predicting risk of adverse drug reactions in older adults

Adverse drug reactions (ADRs) are common in older adults, with falls, orthostatic hypotension, delirium, renal failure, gastrointestinal and intracranial bleeding being amongst the most common clinical manifestations. ADR risk increases with age-related changes in pharmacokinetics and pharmacodynamics, increasing burden of comorbidity, polypharmacy, inappropriate prescribing and suboptimal monitoring of drugs. ADRs are a preventable cause of harm to patients and an unnecessary waste of healthcare resources. Several ADR risk tools exist but none has sufficient predictive value for clinical practice. Good clinical practice for detecting and predicting ADRs in vulnerable patients includes detailed documentation and regular review of prescribed and over-the-counter medications through standardized medication reconciliation. New medications should be prescribed cautiously with clear therapeutic goals and recognition of the impact a drug can have on multiple organ systems. Prescribers should regularly review medication efficacy and be vigilant for ADRs and their contributory risk factors. Deprescribing should occur at an individual level when drugs are no longer efficacious or beneficial or when safer alternatives exist. Inappropriate prescribing and unnecessary polypharmacy should be minimized. Comprehensive geriatric assessment and the use of explicit prescribing criteria can be useful in this regard.

Clinical Weighting of Drug-Drug Interactions in Hospitalized Elderly

Adverse drug reactions impact on patient health, effectiveness of pharmacological therapy and increased health care costs. This investigation intended to detect the most critical drug-drug interactions in hospitalized elderly patients, weighting clinical risk. We conducted a cross-sectional study between January and April 2014; all patients 70 years or older, hospitalized for >24 hr and prescribed at least one medication were included in the study. Drug-drug interactions were estimated by combining Stockley's, Hansten and Tatro drug interactions. Drug-drug interactions were weighted using a risk-analysis method based on failure modes, effects and criticality analysis. We calculated a criticality index for each drug involved in the drug-drug interactions based on the severity of the interaction mechanism, the frequency the drug was involved in drug-drug interactions and the risk of drug-drug interactions in patients with impaired renal function. The average number of drugs consumed in the hospital was 6 ± 2.69, involving 160 active ingredients. The most frequent were as follows: Furosemide, followed by Enalapril. Of drug-drug interactions, 2% were classified as contraindicated, 14% advised against and 83% advised caution during the hospital stay. Thirty-four drug-drug interactions were assessed, of which 23 were pharmacodynamic drug-drug interactions and 12 were pharmacokinetic drug-drug interactions (1 was both). The clinical risk calculated for each drug-drug interaction included heparins + non-steroidal anti-inflammatory drugs (NSAIDs) or Digoxin + Calcium Gluconate, cases which are pharmacodynamic drug-drug interactions with agonist effect and clinical risk of bleeding, one of the most common clinical risks in the hospital. An index of clinical risk for drug-drug interactions can be calculated based on severity by the interaction mechanism, the frequency that the drug is involved in drug-drug interactions and the risk of drug-drug interactions in an elderly patient with impaired renal function.

Appropriate prescribing in the elderly: Current perspectives

Advances in medical therapeutics have undoubtedly contributed to health gains and increases in life expectancy over the last century. However, there is growing evidence to suggest that therapeutic decisions in older patients are frequently suboptimal or potentially inappropriate and often result in negative outcomes such as adverse drug events, hospitalisation and increased healthcare resource utilisation. Several factors influence the appropriateness of medication selection in older patients including age-related changes in pharmacokinetics and pharmacodynamics, high numbers of concurrent medications, functional status and burden of co-morbid illness. With ever-increasing therapeutic options, escalating proportions of older patients worldwide, and varying degrees of prescriber education in geriatric pharmacotherapy, strategies to assist physicians in choosing appropriate pharmacotherapy for older patients may be helpful. In this paper, we describe important age-related pharmacological changes as well as the principal domains of prescribing appropriateness in older people. We highlight common examples of drug-drug and drug-disease interactions in older people. We present a clinical case in which the appropriateness of prescription medications is reviewed and corrective strategies suggested. We also discuss various approaches to optimising prescribing appropriateness in this population including the use of explicit and implicit prescribing appropriateness criteria, comprehensive geriatric assessment, clinical pharmacist review, prescriber education and computerized decision support tools.

Drug therapies in older adults (part 1)

Prescribing for older adults represents a significant challenge as the UK population ages. Physiological decline and the rising prevalence of frailty increase the likelihood of altered pharmacodynamics and pharmacokinetics, suboptimal prescribing and adverse effects among this growing cohort of the population. In the first of two articles, we begin by considering these issues and posit four key questions which should be considered when prescribing for older adults. Does this agent reflect the priorities of the patient? Are there alternatives - with greater efficacy, effectiveness or tolerability - that might be considered? Are the dose, frequency and formulation appropriate? How does this prescription relate to concurrent medication? We also describe current drug therapies in two disease states with a predilection for older adults: Alzheimer's disease (AD) and osteoporosis. Using these examples we highlight the limitations of evidence-based medicine and guidelines in this cohort of the population, illustrating the reliance on sub-group analysis to demonstrate the efficacy of drug therapies for older adults in osteoporosis and the underutilisation of appropriate treatments for patients with AD as a result of flawed guidelines.

Impact of specific Beers Criteria medications on associations between drug exposure and unplanned hospitalisation in elderly patients taking high-risk drugs: a case-time-control study in Western Australia

BACKGROUND

Certain broad medication classes have previously been associated with high rates of hospitalisation due to related adverse events in elderly Western Australians, based on clinical coding recorded on inpatient summaries. Similarly, some medications from the Beers Criteria, considered potentially inappropriate in older people, have been linked with an increased risk of unplanned hospitalisation in this population.

OBJECTIVE

Our objective was to determine whether risk estimates of drug-related hospitalisations are altered in elderly patients taking 'high-risk drugs' (HRDs) when specific Beers potentially inappropriate medications (PIMS) are taken into consideration.

METHODS

Using the pharmaceutical claims of 251,305 Western Australians aged ≥65 years (1993-2005) linked with other health data, we applied a case-time-control design to estimate odds ratios (ORs) for unplanned hospitalisations associated with anticoagulants, antirheumatics, opioids, corticosteroids and four major cardiovascular drug groups, from which attributable fractions (AFs), number and proportion of drug-related admissions were derived. The analysis was repeated, taking into account exposure to eight specific PIMs, and results were compared.

RESULTS

A total of 1,899,699 index hospitalisations were involved. Of index subjects, 12-57 % were exposed to each HRD at the time of admission, although the proportions taking both an HRD and one of the selected PIMs were much lower (generally ≤2 %, but as high as 8 % for combinations involving temazepam and for most PIMs combined with hypertension drugs). Included PIMs (indomethacin, naproxen, temazepam, oxazepam, diazepam, digoxin, amiodarone and ferrous sulphate) all tended to increase ORs, AFs and drug-related hospitalisation estimates in HRD combinations, although this was less evident for opioids and corticosteroids. Indomethacin had the greatest overall impact on HRD ORs/AFs. Indomethacin (OR 1.40; 95 % confidence interval [CI] 1.27-1.54) and naproxen (OR 1.22; 1.14-1.31) were associated with higher risks of unplanned hospitalisation than other antirheumatics (overall OR 1.09; 1.06-1.12). Similarly, among cardiac rhythm regulators, amiodarone (OR 1.22; 1.13-1.32) was riskier than digoxin (OR 1.08; 1.04-1.13). For comparisons of drug-related hospitalisation estimates, temazepam yielded the greatest absolute increases, especially with hypertension drugs.

CONCLUSIONS

Indomethacin and temazepam should be prescribed cautiously in elderly patients, especially in drug combinations. Furthermore, it appears other antirheumatics should be favoured over indomethacin/naproxen and, in situations where both drugs may be appropriate, digoxin over amiodarone. Our methodology may help assess the safety of new medications in drug combinations in preliminary pharmacovigilance investigations.

A descriptive study of adrenal crises in adults with adrenal insufficiency: increased risk with age and in those with bacterial infections

BACKGROUND

An adrenal crisis (AC) is a major cause of morbidity in hypoadrenal patients. However, there is little information available on the incidence and underlying causes of AC.

METHODS

The aim of the present study was to describe the incidence of AC in New South Wales (NSW), Australia. Using a health department database, we selected de-identified data on all adults aged 20 years and over who were treated in any hospital in NSW between July1, 2000-June 30, 2011, with either a principal or secondary diagnosis of an AC. AC admission rates were calculated overall and within age categories. Frequencies of co-morbid diagnoses were analysed by age and sex groups. Poisson regression was used to assess the significance of the observed change in AC related admissions with age, while controlling for any secular trends by including year in the model. Chi sq tests were used to assess the differences in frequencies of categorical variables between groups.

RESULTS

824 patients received treatment for an AC in hospital, corresponding to 74.9 admissions/year. The majority (62.5%) of the patients were women and 52.8% were aged 60 years and over. Admission rates were significantly associated with increasing age (p < 0.0001). Patients in the 60-69, 70-79 and 80+ age groups had the highest average admission rates (24.3, 35.2 and 45.8 per million/year). A principal or secondary diagnosis of an infection was reported in 317 (38.5%) patients and infection was significantly associated with age (p < 0.0001) with older patients having the highest proportion of cases. The most frequent infections were pneumonia/lower respiratory tract infection in 85 (10.3%) cases and urinary tract infection (UTI) in 82 (10.0%) patients. Women experienced 78.0% of the reported UTIs. There were 125 patients (15.2%) with an AC and a record of gastroenteritis. Twenty-six (3.2%) patients died in hospital but, of these, only 4 deaths (0.9%) were recorded among the 467 patients with a principal diagnosis of an AC.

CONCLUSIONS

The incidence of AC increases with age. Infections, especially bacterial infections, are associated with the incidence of ACs and this increases with age.

Bleeding complications in cutaneous surgery for patients on warfarin who have skin cancer of the head and neck

Many patients who have operations on the head and neck for skin cancer also take warfarin to prevent thromboembolic events, and there is still debate about whether treatment should be continued, adjusted, or temporarily stopped. The main concern is to balance the risk of haemorrhagic and thromboembolic events. In this prospective controlled study we compared bleeding complications in operations for skin cancer of the head and neck between 86 patients who took warfarin (100 tumours) and 87 (100 tumours) who did not. Surgeons of different grades did the operations under the guidance of the same consultant. All those on warfarin had above normal international normalised ratios (INRs) (mean (SD) 2.5 (0.51), mode 2.6, range 1.1-4.0). In the warfarin group 8% of excisions had a bleeding complication compared with 9% in the control group. One patient in each group suffered a severe bleed that required a return to theatre. The difference in tendency to bleed between the groups was not significant (p=0.30), and the site and type of reconstruction did not influence the risk of bleeding significantly. This study shows that patients on warfarin who are within the normal therapeutic range, can be operated on safely for skin cancer by all levels of trained staff.

Association between potentially inappropriate medications from the Beers criteria and the risk of unplanned hospitalization in elderly patients

BACKGROUND

Predisposition to adverse drug events with advancing age has led to the development of lists of potentially inappropriate medications (PIMs) to be avoided in the elderly, such as the Beers Criteria. The prevalence of Beers medications has been studied widely, but it is still unclear whether PIM use is predictive of adverse events in older people.

OBJECTIVES

To examine potential associations between exposure to PIMs from the general Beers list and unplanned hospitalizations in elderly Western Australians.

METHODS

Using an enhanced case-time-control design and conditional logistic regression applied to the pharmaceutical claims and other linked health data of 251 305 Western Australians aged ≥65 years (1993-2005), odds ratios for unplanned hospitalization were obtained, from which attributable fractions, number and proportion of hospitalizations associated with drug exposure were derived.

RESULTS

Based on the health profiles of 383 150 hospitalized index subjects, overall PIM exposure was associated with an elevated risk of unplanned hospitalization (adjusted odds ratio = 1.18; 95% confidence interval = 1.15-1.21), this estimated risk increasing with the number of different PIMs and PIM quantity taken. Fifteen percent of unplanned hospitalizations in exposed index subjects (1980 per year) were attributed to PIM exposure. Patients taking meperidine (pethidine), nitrofurantoin, promethazine, indomethacin, and thioridazine appeared to be at particularly high risk of unplanned hospitalization, whereas temazepam, oxazepam, diazepam, digoxin, amiodarone, ferrous sulfate, and naproxen were attributed the greatest numbers of unplanned hospitalizations.

CONCLUSIONS

Due caution prescribing Beers medications in the elderly seems justified, paying particular attention to PIMs listed above and to the concurrent use of multiple PIMs. Our results also support the retention of specific medications on PIM lists in future developments.

Are high-care nursing home residents at greater risk of unplanned hospital admission than other elderly patients when exposed to Beers potentially inappropriate medications?

AIM

To compare the risk of unplanned hospitalization in high-care nursing home residents taking Beers potentially inappropriate medications (PIM) against that of other elderly.

METHODS

Using an enhanced case-time-control design and conditional logistic regression applied to the pharmaceutical claims and other linked data of 245436 Western Australians aged ≥ 65 years (1993-2005), the study derived odds ratios for unplanned hospitalization in each group, from which attributable fractions, numbers, proportions and rates of PIM-related admissions were derived.

RESULTS

Overall, 383150 unplanned hospitalizations were identified. PIM exposure was associated with a similar proportional increase in unplanned hospitalizations in high-care nursing home residents as in other older people; adjusted OR 1.21 (95% CI 1.10-1.34; attributable fraction 17.5%) versus OR 1.19 (95% CI 1.16-1.21; attributable fraction 15.7%). However, high-care nursing home residents had much higher estimated rates of hospitalizations attributed to Beers medications than other elderly (3951 vs 1394 per 100000 person-years). The relative risk of unplanned hospitalization rose similarly in both groups with increasing numbers of different PIM taken (OR 5.1 for 10 vs 0 PIM), but was affected more markedly by 3-month PIM consumption in nursing home residents (OR 4.85, 95% CI 2.40-9.83 for 900 vs 0 PIM daily doses) than in other older adults (OR 2.10, 95% CI 1.73-2.55).

CONCLUSIONS

High-care nursing home residents do not appear to have a greater relative risk of unplanned hospitalization when given PIM, but do incur a higher absolute burden than other older adults. Physicians should exert caution with Beers medications in all older patients, restricting the number of different PIM and PIM quantity prescribed whenever possible.

The effect of aging on dopamine release and metabolism during sevoflurane anesthesia in rat striatum: an in vivo microdialysis study

We have previously reported that halothane anesthesia increases extracellular concentrations of dopamine (DA) metabolites in rat striatum using in vivo microdialysis techniques. Aging induces many changes in the brain, including neurotransmission. However, the relationship between aging and changes in neurotransmitter release during inhalational anesthesia has not been fully investigated. The aim of the present investigation was to evaluate the effect of sevoflurane on methamphetamine (MAPT)-induced DA release and metabolism in young and middle-aged rats. Male Sprague-Dawley rats were implanted with a microdialysis probe into the right striatum. The probe was perfused with a modified Ringer's solution and 40μl of dialysate was directly injected to an HPLC every 20min. Rats were administered saline, the same volume of 2mgkg(-1) MAPT intraperitoneally, or 5μM MAPT locally perfused. After treatments, the rats were anesthetized with 1% or 3% sevoflurane for 1h. Sevoflurane anesthesia significantly increased the extracellular concentration of DA only in middle-aged rats (52-weeks-old). In young rats (8-weeks-old), sevoflurane significantly enhanced MAPT-induced DA when administered both intraperitoneally and perfused locally, whereas no significant additive interaction was found in middle-aged rats. These results suggest that aging changes DA release and metabolism in rat brains primarily by decreasing the DA transporter.

The prevalence of herbal medicine home use and concomitant use with pharmaceutical medicines in Jamaica

ETHNOPHARMACOLOGICAL RELEVANCE

The work described in this paper aimed to study the prevalence of herbal medicine use in treating illness and concomitant use with pharmaceutical medicines in Jamaica.

MATERIALS AND METHODS

A survey using a structured questionnaire was administered by a trained interviewer to randomly selected adults in systematically selected households within randomly selected urban and rural clusters. Categorical data analysis was performed using Stata version 10 software.

RESULTS

91.4%(372/407) of selected people agreed to participate. 72.6%(270/372) self-medicated with herbs within the previous year. Commonly treated were illnesses of the respiratory system (RS, 77.8%(210/270)), gastro-intestinal tract (GIT, 53.3%(144/270)) and health maintenance using tonics (29.6%(80/270)). 26.7%(72/270) of respondents used pharmaceuticals concomitantly with medicinal plants. Commonly treated were illnesses of the RS (20.4%(55/270)), GIT (13.7%(37/270)) and hypertension (10.0%(27/270)). 19.4% (14/72) of physicians knew of such practices. There was significant association of herb use with/without drugs with age (p<0.001), employment status (p<0.001), religion (p=0.004), gender (p=0.02) and educational level (p=0.031). Thus prevalence of herb use alone was greatest amongst people aged 35-44 and 45-54 years; those employed; Rastafarians; those without health insurance; males and people who had completed secondary education. Whilst prevalence of concomitant herb-drug use was greater amongst people aged 65 years and older; those retired; those of religions other than Rastafarians and Christians, females and people who had attained primary education and below.

CONCLUSIONS

Self-medication with herbs in Jamaica is highly prevalent and highest for self-limiting conditions of the RS, GIT and health maintenance with tonics. Concomitant herb and drug use is highest for self-limiting conditions of the RS, GIT and hypertension, and the use of combined therapy highlights the need for investigations on potential drug-herb interactions. Physicians have limited awareness and knowledge of such concomitant usage, further highlighting the need for increased dialogue with patients, knowledge of medicinal plants and their uses and a heightened pharmacovigilance to avoid adversities that may arise from potential drug-herb interactions.