Selegiline Side Effects

Reported Selegiline side effects

Oral selegiline in Parkinson's disease In the only parallel placebo-controlled Parkinson's disease trial described in the US label (49 patients on selegiline, 50 on placebo), nausea occurred in 10 against 3 patients, dizziness, light-headedness or fainting in 7 against 1, abdominal pain in 4 against 2, confusion in 3 against none, hallucinations in 3 against 1 and dry mouth in 3 against 1 (US prescribing information for selegiline hydrochloride tablets). The label states that selegiline can worsen levodopa side effects, reports intense urges to gamble or have sex with drugs that raise dopamine activity, and notes that people with Parkinson's disease have a 2 to about 6 times higher risk of melanoma, of uncertain cause (US prescribing information for selegiline hydrochloride tablets). In a Cochrane review of early Parkinson's disease trials, withdrawals because of side effects were more frequent with MAO-B inhibitors (odds ratio 2.36) (PMID: 16034956). Dyskinesias were more frequent (34 against 19 percent) but freezing of gait less frequent (16 against 29 percent) in people who stayed on selegiline in the DATATOP extension (PMID: 12112107). The Emsam skin patch in depression In placebo-controlled depression trials (817 patients on Emsam, 668 on placebo), application site reactions affected 24 against 12 percent, headache 18 against 17 percent, insomnia 12 against 7 percent, diarrhea 9 against 7 percent and dry mouth 8 against 6 percent, and 7.1 percent against 3.6 percent stopped because of an adverse reaction (US prescribing information for Emsam). Low systolic blood pressure occurred in 3.0 against 1.5 percent, mania in 8 of 2,036 patch-treated patients (0.4 percent), and the label carries a boxed warning that antidepressants increased suicidal thoughts and behaviors in pediatric and young adult patients in short-term studies (US prescribing information for Emsam). Blood pressure crises The oral label reports rare hypertensive reactions after tyramine-containing foods at the labeled dose and one hypertensive crisis in a patient also taking ephedrine (US prescribing information for selegiline hydrochloride tablets). The Emsam label states that hypertensive crises after tyramine-rich food or drink can be fatal and that intracranial bleeding has been reported with the rise in blood pressure (US prescribing information for Emsam). Serotonin syndrome and drug reactions Stupor, muscle rigidity, severe agitation and high temperature, and in some cases death, have been reported with selegiline plus meperidine, and severe toxicity including deaths with selegiline plus tricyclic antidepressants or selective serotonin reuptake inhibitors (US prescribing information for selegiline hydrochloride tablets). The Emsam label describes potentially life-threatening serotonin syndrome when MAO inhibitors are combined with serotonergic drugs (US prescribing information for Emsam). Overdose Some people exposed to 600 mg of racemic (d,l) selegiline during its development had severe low blood pressure and agitation, and the oral label expects overdose to inhibit both MAO-A and MAO-B (US prescribing information for selegiline hydrochloride tablets). Deaths in Parkinson's disease trials In the open UK trial of 520 people with early Parkinson's disease, mortality was 1.57 times higher with levodopa plus selegiline than with levodopa alone after 5 to 6 years (PMID: 8555803). With longer follow-up the hazard ratio was 1.32 and not significant in the original arms, 1.33 (95 percent CI 1.02 to 1.74) when all randomized subjects were included, and the excess was in deaths attributed to Parkinson's disease; the selegiline arm was stopped in 1995 (PMID: 9583926). DATATOP found no effect of selegiline on deaths over 8.2 years (PMID: 9506548), a 1998 meta-analysis of five trials found a hazard ratio of 1.02 (PMID: 9748034), a 2004 meta-analysis of 17 trials an odds ratio of 1.13, not significant (PMID: 15310558), and a 2005 Cochrane review an odds ratio of 1.15 whose confidence interval did not exclude a small increase (PMID: 16034956).

When to continue, reduce, or stop Selegiline

Selegiline contraindications

Labeled contraindications for oral selegiline are known hypersensitivity to selegiline and use with meperidine, a contraindication that the label notes is often extended to other opioids (US prescribing information for selegiline hydrochloride tablets). Labeled contraindications for Emsam are use with selective serotonin reuptake inhibitors, serotonin and norepinephrine reuptake inhibitors, clomipramine, imipramine, meperidine, tramadol, methadone, pentazocine, propoxyphene, dextromethorphan or carbamazepine; children under 12; and pheochromocytoma (US prescribing information for Emsam). The label requires at least 2 weeks after stopping Emsam before starting a contraindicated drug, and at least 5 weeks after stopping fluoxetine before starting Emsam (US prescribing information for Emsam). Doses above the labeled range are a concern: the oral label warns that selectivity for MAO-B is reduced as the daily dose rises, with the risks of non-selective MAO inhibition (US prescribing information for selegiline hydrochloride tablets), and healthy volunteers taking 30 mg a day became 2 to 4 times more sensitive to tyramine (PMID: 3145523). The Emsam label requires a low-tyramine diet at the 9 and 12 mg per 24 hours strengths, from the first day until 2 weeks after a dose reduction or stop, and lists aged cheeses, air-dried, aged or fermented meats, tap beer, concentrated yeast extract, sauerkraut and most soy products among the foods to avoid (US prescribing information for Emsam). Antidepressants, Emsam included, can trigger mania in people with bipolar disorder, and the label calls for screening before treatment (US prescribing information for Emsam). The Emsam label advises against exposing the patch site to heating pads, saunas, hot tubs or prolonged direct sunlight, because heat may increase absorption (US prescribing information for Emsam). There are no adequate studies in pregnant women; in rabbits the highest dose increased fetal loss, and in rats high doses increased stillbirths and reduced pup survival (US prescribing information for selegiline hydrochloride tablets).

Why vendor quality drives Selegiline side-effect frequency

Research-compound communities consistently report that adverse-event frequency tracks with source quality. Three reasons: (1) impurity profiles vary by lab (residual synthesis byproducts can trigger reactions); (2) mislabeled mass means actual dose can be 50-150% of stated dose; (3) reconstitution-grade water and capping methodology affect long-term storage stability. COA-verified vendors with published HPLC data minimize all three failure modes. Check a vendor's COA record and Trust Score before you buy.

Selegiline side effects FAQ

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