Apokyn Side Effects, and Drug Interactions - Apomorphine

Apokyn Side Effects, and Drug Interactions - Apomorphine

SIDE EFFECTS

Adverse Event Incidence in Controlled Clinical Studies: APOKYN™ has been administered to 550 Parkinson’s disease patients who were taking some form of L-Dopa along with other Parkinson’s disease medications. Eighty-six percent of patients were taking a concomitant dopamine agonist. All patients had some degree of spontaneously occurring hypomobility ("off episodes") at baseline. Adverse events were recorded by the clinical investigators using terminology of their own choosing. To provide a meaningful estimate of the proportion of individuals having adverse events, similar types of events were grouped into a smaller number of standardized categories using MEDRA dictionary terminology.

The most common adverse events seen in controlled trials were yawning, dyskinesias, nausea and/or vomiting, somnolence, dizziness, rhin-orrhea, hallucinations, edema, chest pain, increased sweating, flushing, and pallor.

The most extensive experience with apomorphine in randomized, controlled trials comes from a multicenter randomized placebo-controlled parallel group trial conducted in apomorphine-naïve PD patients treated for up to 4 weeks (Table 1). Individual apomorphine doses in this trial ranged from 2-10 mg, optimized to achieve control of symptoms comparable to each patient’s response to his or her usual dose of L-dopa. The prescriber should be aware that these figures cannot be used to predict the incidence of adverse events in the course of usual medical practice where patient characteristics and other factors differ from those that prevailed in the clinical studies. Similarly, the cited frequencies cannot be compared with figures obtained from other clinical investigations involving different treatments, uses, and investigators. However, the cited figures do provide the prescribing physician with some basis for estimating the relative contribution of drug and nondrug factors to the adverse-event incidence rate in the population studied.

APOKYN has been administered to 550 patients; 89% had at least one adverse event (AE). The most common AEs in addition to those in Table 1 (occurring in at least 5% of the patients and at least plausibly related to treatment) in descending order were injection site complaint, fall, arthralgia, insomnia, headache, depression, urinary tract infection, anxiety, congestive heart failure, limb pain, back pain, Parkinson’s disease aggravated, pneumonia, confusion, sweating increased, dyspnea, fatigue, ecchymosis, constipation, diarrhea, weakness, and dehydration.

A rarely reported motivation for apomorphine abuse (escalation of dose beyond prescribed frequency) is the use of apomorphine to attempt to avoid all symptoms of all "off" events when "off" events occur frequently. A second, rarely reported, motivation for apomorphine abuse is a psychosexual reaction related to the stimulation of penile erection and increase in libido. Adverse events that have been reported in males with overuse include frequent penile erections, atypical sexual behavior, heightened libido, dyskinesias, agitation, confusion, and depression. No studies have been conducted to evaluate the potential for dependence when apomorphine is used as acute (rescue) treatment of "off" episodes in the patients with "on/off" or "wearing-off" effects associated with late stage Parkinson’s disease.

Based on reports of profound hypotension and loss of consciousness when apomorphine was administered with ondansetron, the concomitant use of apomorphine with drugs of the 5HT³ antagonist class (including, for example, ondansetron, granisetron, dolasetron, palonosetron, and alosetron) is contraindicated (see Contraindications).

The following adverse events were experienced more commonly in patients receiving concomitant antihypertensive medications or vasodilators (n = 94) compared to patients not receiving these concomitant drugs (n = 456): hypotension 10% vs 4%, myocardial infarction 3% vs 1%, serious pneumonia 5% vs 3%, serious falls 9% vs 3%, and bone and joint injuries 6% vs 2%. The mechanism underlying many of these events is unknown, but may represent increased hypotension (see WARNINGS: Symptomatic Hypotension). Dopamine Antagonists

Since apomorphine is a dopamine agonist, it is possible that dopamine antagonists, such as the neuroleptics (phenoth-iazines, butyrophenones, thioxanthenes) or metoclopramide, may diminish the effectiveness of APOKYN. Patients with major psychotic disorders, treated with neuroleptics, should be treated with dopamine agonists only if the potential benefits outweigh the risks.

Caution should be exercised when prescribing apomorphine concomitantly with drugs that prolong the QT/QTc interval (see WARNINGS: QT Prolongation and Potential for Proarrhythmic Effects).

There are no known interactions between APOKYN and laboratory tests.