Pharmacodynamic and pharmacokinetic considerations in geriatric psychopharmacology.

Age-associated decreases in metabolism and elimination of drugs are sufficient to give one pause before prescribing drugs in the elderly particularly if multiple drugs are to be used. When one factors in concomitant drugs that may inhibit P450-mediated metabolism of other more toxic drugs, genetic deficiency of P450 enzymes, and medical illnesses such as liver and renal failure that will lead to further elevation of drug levels and delay in drug clearance, the likelihood of adverse events when multiple drugs are used in the elderly becomes truly dizzying. In consideration of the pharmacologic principles discussed, when prescribing drugs in the elderly, one might add to the often heard recommendation, "Start low and go slow," a third admonition, "Keep it as simple as possible!"

Prevalence of asymptomatic chlamydial cervical infection in active duty Army females.

Four hundred seventy-six consecutive active duty Army females who presented for routine pap smears were screened for Chlamydia trachomatis and Neisseria gonorrhea. Thirty-nine of 476 (8.2%) tested positive for chlamydia using the Chlamydiazyme enzyme immunoassay. All patients with positive tests for chlamydia were asymptomatic and had normal pelvic exams. The average age of patients testing positive for chlamydia was 23.9. Only 6 of the 39 patients with chlamydia were older than 30. Tests for gonorrhea and pap smear results had little correlation with patients testing positive for chlamydia. The high prevalence of chlamydia in this population of asymptomatic women makes it probable that screening similar populations of patients would be more cost-effective than treating the complications of this disease.

Pharmacokinetics of selective serotonin reuptake inhibitors: clinical relevance.

Selective serotonin reuptake inhibitors (SSRIs) are a safe and effective class of drugs for treatment of depressive and obsessive-compulsive disorders. Among this class of drugs, pharmacodynamic actions, antidepressant efficacy and adverse effect profiles are remarkably similar. However, pharmacokinetic profiles of SSRIs are substantially different especially with respect to pharmacokinetically mediated drug-drug interactions. For example, fluoxetine and paroxetine produce clinically significant inhibition of cytochrome P450 2D6 at their usually effective antidepressant dose, whereas citalopram, fluvoxamine or sertraline do not. There is also a substantial difference between SSRIs with respect to their capacity to inhibit other cytochrome P450 enzymes including IA2, 2C19, 3A4 and possibly 2C9/10. The inhibition of these enzymes can reduce the clearance of concomitantly administered drugs which are dependent on oxidative metabolism mediated by these enzymes as a necessary prerequisite for their subsequent elimination. The accumulation of unusually high levels of such drugs can result in an increase in nuisance and/or more serious, even life-threatening, adverse effects depending on the pharmacology of the co-prescribed drug. Knowledge of these issues will enable clinicians to predict and make appropriate dose adjustments to avoid potential drug-drug interactions that otherwise could result in toxicity.

Anticholinergic toxicity masquerading as neuroleptic malignant syndrome: a case report and review.

Patients who present with acute neuropsychiatric syndromes pose difficult diagnostic and treatment challenges. A history of psychiatric illness and treatment with psychotropic medication may be valuable clues to diagnosis and management of such patients. However, this information may also tempt a clinician to focus on a premature diagnosis, excluding other important possibilities. A case of a 42-year-old male with recurrent psychotic illness who developed an abrupt deterioration in mental and physical status is presented. Despite an initial good response to physostigmine, he was diagnosed with neuroleptic malignant syndrome and did not receive subsequent treatment with cholinesterase inhibitors. The patient expired within hours of arriving in the emergency room. The postmortem benztropine level was elevated, leading to the attribution of death to anticholinergic toxicity. This case serves to illustrate the difficulties in distinguishing features of anticholinergic toxicity and neuroleptic malignant syndrome.

Death due to alcoholic complications in a young woman with a severe eating disorder: a case report.

OBJECTIVE: Recently, a good deal of attention has been focused on alcoholism and eating disorders as comorbid conditions. Early identification of biologic, psychologic, and sociocultural factors that contribute to comorbid alcoholism and eating disorders may improve the outcome for such patients. METHOD: The following case report is of a 26-year-old woman who developed a severe eating disorder in her early teens that was followed by alcoholism. RESULTS: The combination of eating disorder and alcoholism in this patient led to approximately 70 hospitalizations for medical complications of her alcoholism. This paper chronicles her last few living months including her death due to alcoholic complications.