Severe hyperpyrexia due to tranylcypromine-amphetamine toxicity

Combining Stimulants and Monoamine Oxidase Inhibitors: A Reexamination of the Literature and a Report of a New Treatment Combination

This report reviews the medical literature on combining stimulants with monoamine oxidase inhibitors. A case is also presented documenting successful treatment of major depressive disorder and comorbid attention-deficit/hyperactivity disorder using the previously undocumented combination of transdermal selegiline and lisdexamfetamine. This combination should be used cautiously and with ongoing monitoring of heart rate and blood pressure.

Systematic overview of drug interactions with antidepressant medications

OBJECTIVE

Antidepressants are commonly used drugs with potential for numerous drug interactions. This study aims to systematically review the literature on drug interactions with antidepressants.

METHODS

We searched MEDLINE (1966 to November 2003) and EMBASE (1980 to 2003), using the heading drug interactions combined with individual antidepressant names. We restricted searches to English-language articles and human studies. We screened drug interaction texts and review articles for relevant studies. We included articles reporting original human data on drug interactions with antidepressants commonly used in North America. Articles were independently evaluated by 2 reviewers on clinical effect, clinical significance, and quality of evidence. Discrepancies were resolved by consensus.

RESULTS

There were 904 eligible interactions, involving 9509 patients, for a total of 598 summary interactions. Of these, 439 (73%) demonstrated an interaction, 148 (25%) had no effect, and 11 (2%) had conflicting evidence. For 510 interactions (85%), the quality of evidence was poor. It was fair for 67 (11%) interactions and good for 10 (2%) interactions. There were no interactions with excellent quality of evidence. There were 145 (24%) interactions of major clinical significance. These were predominantly hypertensive emergencies and serotonin syndrome. Most interacting drugs had central nervous system (CNS) activity. As expected, monoamine oxidase inhibitors (MAOIs) appear to be the most problematic family in terms of potential for serious drug interactions.

CONCLUSIONS

Drug interactions with antidepressants are an important cause for concern, but this concern is based primarily on poor evidence. We recommend caution when combining antidepressants with other CNS drugs, particularly when coadministering MAOIs with other substances.

Pharmacokinetic and pharmacodynamic drug interactions in the treatment of attention-deficit hyperactivity disorder

The psychostimulants methylphenidate, amphetamine and pemoline are among the most common medications used today in child and adolescent psychiatry for the treatment of patients with attention-deficit hyperactivity disorder. Frequently, these medications are used in combination with other medications on a short or long term basis. The present review examines psychostimulant pharmacology, summarises reported drug-drug interactions and explores underlying pharmacokinetic and pharmacodynamic considerations for interactions. A computerised search was undertaken using Medline (1966 to 2000) and Current Contents to provide the literature base for reports of drug-drug interactions involving psychostimulants. These leads were further cross-referenced for completeness of the survey. Methylphenidate appears to be more often implicated in pharmacokinetic interactions suggestive of possible metabolic inhibition, although the mechanisms still remain unclear. Amphetamine was more often involved in apparent pharmacodynamic interactions and could potentially be influenced by medications affecting cytochrome P450 (CYP) 2D6. No published reports of drug interactions involving pemoline were found. The alpha2-adrenergic agonists clonidine and guanfacine have been implicated in several interactions. Perhaps best documented is their antagonism by tricyclic antidepressants and phenothiazines. In additional, concurrent beta-blocker use, or abrupt discontinuation, can lead to hypertensive response. Although there are few published well-controlled interaction studies with psychostimulants and alpha2-adrenergic agonists, it appears that these agents may be safely coadministered. The interactions of monoamine oxidase inhibitors with psychostimulants represent one of the few strict contraindications.

Drug-drug interactions in pediatric psychopharmacology

Serious consequences caused by drug-drug interactions continue to plague contemporary pharmacotherapy. The possibility of a drug-drug interaction should be suspected anytime a new or unexpected effect occurs that complicates the clinical management of a patient in the setting where the patient is receiving more than one drug. In this article, the authors address the mechanisms of pharmacokinetic-based drug-drug interactions focusing on important interactions that may occur with the common medications a pediatrician may prescribe to the child receiving psychoactive medication(s) prescribed by a child psychiatrist.

Drug fever: mechanisms, maxims and misconceptions

Although drug fever is a clinical entity that has received considerable attention in textbooks and review articles, only recently have such writings been subjected to critical analysis. In the present review, mechanisms responsible for drug fever are examined. In addition, published characterizations of the syndrome are compared with the results of a recently published systematic analysis of 148 cases of drug fever. This comparison identified a number of important areas in which descriptions of the clinical entity in textbooks and review articles are at odds with the clinical profile exhibited by actual cases of drug fever.

A case of MAO inhibitor/MDMA interaction: agony after ecstasy

After ingesting 3,4-methylene-dioxy-methamphetamine (MDMA) and the monoamine oxidase (MAO) inhibitor phenelzine, a 50 year old male developed marked hypertension, diaphoresis, altered mental status, and hypertonicity lasting 5-6 hours. This clinical course is typical of interaction between MAO inhibitors and some sympathomimetics including amphetamines. Such interaction has not previously been described involving MDMA. Sympathomimetic-MAO inhibitor interactions can cause excessive release of endogenous bioactive amines (e.g. norepinephrine, serotonin). Hypertensive crisis, intracranial hemorrhage, hypertonicity, and severe hyperthermia have occurred due to sympathomimetic-MAO inhibitor interactions. MDMA shares structural and pharmacologic features with other agents capable of causing this interaction, and this case suggests that MDMA can cause significant toxicity in patients taking MAO inhibitors.

Experimental study on the pathogenesis of heat stroke

A heat-balance study was carried out on conscious rabbits exposed to ambient temperatures (Ta) from 8 degrees to 40 degrees C. At Ta = 40 degrees C, heat gain exceeded heat loss and led to hyperthermia and heat stroke, and the latency for the onset of heat stroke was found to be around 87 minutes. At the onset of heat stroke, the comatose animals showed higher levels of rectal temperature, ear skin blood flow, respiratory evaporative heat loss, metabolic rate, intracranial pressure (ICP), and cerebral water content as compared to those of control animals (kept at an ambient temperature of 24 degrees C). Before the start of heat stress, the animals had an average mean arterial blood pressure (MABP) of 94 mm Hg and cerebral perfusion pressure (CPP) of 80 mm Hg. However, at the onset of heat stroke, the average MABP and CPP decreased to 67 and 19 mm Hg, respectively. The reduction in CPP at the onset of heat stroke was due to both a decrease in MABP and an increase in ICP. In addition, the comatose animals which received an intravenous infusion of 10% glycerol (3 ml/min) had a survival time (interval between onset of heat stroke and death) longer than that of the comatose animals which received the control-vehicle solution. The prolongation of survival time in the glycerol-treated animals may be due to lower rectal temperature, lower cerebral water content, or lower ICP during the development of heat stroke. The present data indicate that not only hyperthermia but also cerebral edema, intracranial hypertension, decreased MABP, and decreased CPP are the main causes of heat stroke. The therapeutic values of glycerol on heat stroke may be related to the depressant action on cerebral edema, intracranial hypertension, and body temperature.

Changes in body temperature after administration of adrenergic and serotonergic agents and related drugs including antidepressants

This survey, the third in a series, presents extensive tabulations of literature, primarily since 1965, on thermoregulatory effects of adrenergic and serotonergic agonists and their antagonists including ergot alkaloids, amphetamines, tryptamines, monoamine oxidase inhibitors, tricyclic and other antidepressants, a variety of other agents which alter presynaptic aminergic mechanisms including reserpine, 6-hydroxydopamine, p-chlorophenylalanine, alpha-methyltyrosines, cocaine, guanethidine and bretylium. The information listed includes the species used, route of administration and dose of drug, the environmental temperature at which the experiments were performed, the number of tests, the direction and magnitude of body temperature change and remarks on the presence of special conditions, such as age or lesions, or on the influence of other drugs, such as antagonists, on the response to the primary drug.