Many people are plagued by migraines. To treat them effectively is sometimes not so easy in more severe cases. For severe migraines with or without aura, as well as cluster headaches, triptans, derivatives of serotonin, are nowadays preferably used. The lead substance is sumatriptan, but several successor substances are now on the market. These include zolmitriptan, which is reported to be more effective than the earlier classes of substances.
What is zolmitriptan?
Zolmitriptan is a selective serotonin agonist from the triptan class, which is mainly used in acute therapy for migraine. However, it is effective only when the headache has already occurred, meaning it cannot prevent a migraine attack. The drug is also intended to provide relief for cluster headaches, which occur much less frequently. Zolmitriptan can be administered in the form of tablets or as a nasal spray, in which case it has the advantage of being absorbed more quickly. In contrast to the original lead substance, sumatriptan, it passes more easily through the blood–brain barrier. As an agonist at serotonin receptors, the drug causes vasoconstriction of cerebral blood vessels, which is thought to improve migraine.
Pharmacologic action
The action of zolmitriptan is due to selective binding to serotonin 5HT1D and -5HT1B receptors. These are located on cerebral blood vessels and presynaptically on neurons. When they are activated, they cause blood vessels to constrict, because the headache first results from a dilation (widening) of the blood vessels. In addition, they ensure reduced release of inflammatory mediators and reduced pain transmission. The half-life of zolmitriptan is relatively short, lasting 2.5 to 3 hours. In the liver, metabolism produces an additional active metabolite that is also involved in the effects of the drug. It is metabolized primarily by the enzyme CYP1A2; to a lesser extent, by MAO-A. As mentioned earlier, zolmitriptan passes the blood-brain barrier very well because its molecular size is very small, allowing it to be readily absorbed into fatty tissues. At the same time, it is also absorbed very quickly through the gastrointestinal tract, reaching effective levels in the blood after about an hour. Not only are headaches relieved, but accompanying symptoms of migraine such as nausea, vomiting and sensitivity to light are also positively influenced. Long-term use also showed consistently good efficacy.
Medical application and use
The mean dose of use is 2.5 milligrams. If possible, it should be taken at the first sign of a migraine attack. While the tablets cannot prevent the headache from occurring, taking them in a timely manner will help provide faster relief. However, the medication can still be taken during the attack. If the dose is not sufficient, it can also be increased to 5 milligrams in consultation with a doctor. More than 2 tablets within 24 hours should not be taken. Use in the form of nasal spray is especially beneficial for those who suffer from severe nausea and vomiting, as well as in the case of severe cluster headache. Food taken at the same time hardly affects absorption. In the context of a hospital stay, the drug is also available as a short infusion.
Risks and side effects
Side effects may occur as a result of taking zolmitriptan. Common side effects include nausea, vomiting, dry mouth, dizziness, and drowsiness. In addition, especially with prolonged use, adverse effects include headache. Occasionally, there is an increase in heart rate or a feeling of tightness in the chest. Rarely, itching of the skin or hives may occur. Very rare side effects include heart attack, angina pectoris, and an increased urge to urinate. It is also important to be aware of possible drug interactions if taken at the same time as other medications. Whether an interaction occurs depends on various factors, so always consult the attending physician.However, simultaneous use with ergot alkaloids should be avoided in any case, as the risk of coronary artery spasm is greatly increased by their additional vasoconstrictive effect. The effect of zolmitriptan is enhanced by moclobemide, cimetidine, fluvoxamine, cigarette smoke and quinolones, so in these cases the dose of zolmitriptan must be reduced and adjusted. If selective serotonin reuptake inhibitors are taken concomitantly, caution should be exercised because there is a risk of dangerous serotonin syndrome, in which too much serotonin accumulates in the nervous system. Due to its vasoconstrictive effect, zolmitriptan is contraindicated in existing coronary artery disease, hypertension, and vascular disease. In case of hypersensitivity, hemiplegic migraine or basilaris migraine, the drug should also not be taken. In case of impaired renal function, dose adjustment should be performed. In pregnancy, zolmitriptan should be taken only if the physician considers it absolutely necessary.
