Ephedrine adverse effects

Moclobemide increased the pressor effect of ephedrine in healthy volunteers, who also had more adverse effects including light-headedness and palpitation (SEDA-18, 16). Thus, moclobemide can potentiate the effect of indirect sympathomimetics such combinations should be used with caution. 

As can be seen from Table I a substantial number of alkaloids display significant insect toxicity, including nicotine, pipeline, lupine alkaloids, caffeine, gramine, strychnine, berberine, ephedrine, and steroidal alkaloids. Only the specialists can tolerate the respective alkaloids. The tobacco homworm (Manduca sexto), for example, can grow on a diet with more than 1% nicotine without any adverse effects. Most of the nicotine is either degraded or directly eliminated via the Malpighian tubules and in feces 182). Because nicotine binds to the acetylcholine (ACH) receptor, it is likely that in Manduca this receptor has been modified in such a way that ACH can still bind, but not nicotine (so-called target site modification). 

Both positive and negative drug interactions have been reported with theophyUine. The usefulness of combination products has also been discussed (SEDA-6, 2) (SEDA-11, 7). The use of combinations compUcates the evaluation of adverse effects, particularly those of theophylline and ephedrine. The hkelihood of adverse effects of each component and synergistic effects between components must be evaluated in relation to the patient s clinical condition. A positive feature is the hkelihood of greater compliance with an effective combination product. 

Many cases of serious adverse effects and even fatalities have been reported that were linked with ephedra or ephedrine administration over the last 10 years. Haller and Benowitz published a review of 140 reports of adverse events related to the use of ephedra alkaloids that were submitted to the FDA between June 1997 and March 1999. Using standardized rating system for assessing causation, 31% of the cases were considered to be definitely or probably related to the use of ephedra alkaloid-containing supplements, and another 31% were deemed to be possibly related. Among these adverse events, 47% involved in cardiovascular symptoms and 18% involved the CNS. Hypertension was the most frequent adverse effect, followed by palpitations, tachycardia, or both stroke and seizures. Ten events led to death and 13 cases produced permanent disability. 

Preexisting medical conditions The likelihood of adverse effects of ephedrine is heightened in individuals with a history of high blood pressure, heart or thyroid disease, diabetes, kidney disease or difficulty urinating, glaucoma, a seizure disorder, depression, prostate enlargement, history of stress, or are involved in stressful activities. 

The ephedra alkaloids are all sympathomimetic amines, which means that a host of drug interactions are theoretically possible. In fact, only a handful of adverse drug interactions have been reported in the peer-reviewed literature. The most important of these involve the monoamine oxidase inhibitors (MAOI). Irreversible, nonselective MAOIs have been reported to adversely interact with indirectly acting sympathomimetic amines present in many cough and cold medicine. In controlled trials with individuals taking moclobemide, ephedrine s effects on pulse and blood pressure were potentiated, but only at higher doses than those currently provided in health supplements (137). Ephe-drine-MAOI interaction may, on occasion, be severe enough to mimic pheo-... 

An article in the Canadian Adverse Reaction Newsletter published their reporting of adverse effects caused by products containing C. aurantium from January 1, 1998 to February 28, 2004 (46). The article lists 16 reports of synephrine associated with cardiovascular events including tachycardia, cardiac arrest, ventricular fibrillation, transient collapse, and blackout. In one case, bitter orange was the sole suspected culprit. In seven others the products also contained caffeine, and in eight cases the product contained both caffeine and ephedrine. Health Canada has issued an advisory stating that synephrine may have effects similar to ephedrine and caution should be used if taking it (47). 

Phenylpropanolamine (PPA). Until recently, PPA was widely available in a number of nonprescription cold medications and diet control products. Adverse effects are similar to those described for ephedrine. In response to an FDA warning of increased risk of hemorrhagic stroke, especially in women, PPA has been withdrawn from the market by most manufacturers. Before this withdrawal, PPA was another popular starting product for synthesis of S(-f-)-methamphetamine. PPA is also a metabolite of ephedrine and pseudoephedrine. 

Because of their adverse effects, the Food and Drug Administration (FDA) has taken action to remove two over-the-counter products that have amphetamine-hke action ephedrine, an agent with actions similar to those of epinephrine and the main active ingredient in the herb ephedra, used for weight loss and in energy-enhancement cold medicines and weight loss... 

The herbal dietary supplement ephedra, commonly known as mahuang, is used as an energy boost and for losing weight. Ephedrine and pseudoephedrine are components of ephedra that have a stimulant and bronchodilation effect. However, ephedra has an adverse effect of palpitations—which can result in stroke. 

Some data surest that an increased frequency of adverse effects occurs when ephedrine is used with theophylline. 

The interaction between ephedrine or pseudoephedrine and urinary alkalinisers are established but reports of adverse reactions in patients appear to be rare. Be aware that any increase in the adverse effects of these drugs (tremor, anxiety, insomnia, tachycardia, etc.) could be due to drug retention brought about by this interaction. Acetazolamide makes the urine alkaline and would be expected to interact with ephedrine and pseudoephedrine in the same way as sodium bicarbonate. 

The toxicity of ephedrine is closely related to adverse cardiovascular events, since the clinical presentation of toxicity reflects the sympathomimetic activity of these agents. The adrenergic effects can shorten cardiac refractory periods, permitting the development of reentrant cardiac arrhythmias. The worst complication related to the use of ephedrine is thrombotic stroke, presumably resulting from vasoconstriction of large cerebral arteries that in turn leads to local thrombosis [71]. Other adverse effects include hypertension, diaphoresis, hypothermia, and agitation. The best treatment in an overdose is the rapid identification of the symptoms followed by supportive management. 

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