RELPAX Film-coated tablet Ref.[8135] Active ingredients: Eletriptan

RELPAX should not be used together with potent CYP3A4 inhibitors e.g., ketoconazole, itraconazole, erythromycin, clarithromycin, josamycin and protease inhibitors (ritonavir, indinavir and nelfinavir).

RELPAX should only be used where a clear diagnosis of migraine has been established. RELPAX is not indicated for the management of hemiplegic, ophthalmoplegic, or basilar migraine.

RELPAX should not be given for the treatment of ‘atypical’ headaches, i.e. headaches, which may be related to a possibly serious condition (stroke, aneurysm rupture) where cerebrovascular vasoconstriction may be harmful.

Eletriptan can be associated with transient symptoms including chest pain and tightness, which may be intense and involve the throat (see section 4.8). Where such symptoms are thought to indicate ischaemic heart disease, no further dose should be taken and appropriate evaluation should be carried out.

Patients with cardiac failure

RELPAX should not be given without prior evaluation, to patients in whom unrecognised cardiac disease is likely, or to patients at risk of coronary artery disease (CAD) [e.g. patients with hypertension, diabetes, smokers or users of nicotine substitution therapy, men over 40 years of age, post-menopausal women and those with a strong family history of CAD]. Cardiac evaluations may not identify every patient who has cardiac disease and, in very rare cases, serious cardiac events have occurred, in patients without underlying cardiovascular disease when 5-HT₁ agonists have been administered. Patients in whom CAD is established, should not be given RELPAX (see section 4.3).

5-HT₁ receptor agonists have been associated with coronary vasospasm. In rare cases, myocardial ischaemia or infarction, have been reported with 5-HT₁ receptor agonists.

Undesirable effects may be more common during concomitant use of triptans and herbal preparations containing St. John’s wort (Hypericum perforatum).

Within the clinical dose range, slight and transient increases in blood pressure have been seen with eletriptan doses of 60 mg or greater. However, these increases have not been associated with clinical sequelae in the clinical trial programme. The effect was much more pronounced in renally impaired and elderly subjects. In renally impaired subjects, the range of mean maximum increases in systolic blood pressure was 14-17mmHg (normal 3mmHg) and for diastolic blood pressure was 14-21mmHg (normal 4mmHg). In elderly subjects, the mean maximum increase in systolic blood pressure was 23mmHg compared with 13mmHg in young adults (placebo 8mmHg). Post-marketing reports of increases in blood pressure have also been received for patients taking 20 and 40 mg doses of eletriptan, and in non-renally impaired and non-elderly patients.

Medication overuse headache (MOH)

Prolonged use of any painkiller for headaches can make them worse. If this situation is experienced or suspected, medical advice should be obtained and treatment should be discontinued. The diagnosis of MOH should be suspected in patients who have frequent or daily headaches despite (or because of) the regular use of headache medications.

Serotonin syndrome

Serotonin syndrome (including altered mental status, autonomic instability and neuromuscular abnormalities) has been reported following concomitant treatment with triptans and selective serotonin reuptake inhibitors (SSRIs) or serotonin noradrenaline reuptake inhibitors (SNRIs). These reactions can be severe. If concomitant treatment with eletriptan and an SSRI or SNRI is clinically warranted, appropriate observation of the patient is advised, particularly during treatment initiation, with dose increases, or with addition of another serotonergic medication (see section 4.5).

Excipients

This medicinal product contains lactose. Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine.

This medicinal product also contains sunset yellow which may cause allergic reactions.

RELPAX 20 mg tablets contain less than 1 mmol sodium (23 mg) per tablet. Patients on low sodium diets can be informed that these medicinal products are essentially ‘sodium free’.

Effect of other medicinal products on eletriptan

In the pivotal clinical trials of eletriptan no evidence of interaction with beta-blockers, tricyclic antidepressants, selective serotonin reuptake inhibitors and flunarizine was reported but data from formal clinical interaction studies with these medicinal products are not available (other than propranolol, see below).

Population pharmacokinetic analysis of clinical studies has suggested that the following medicinal products (beta-blockers, tricyclic antidepressants, selective serotonin re-uptake inhibitors, oestrogen based hormone replacement therapy, oestrogen containing oral contraceptives and calcium channel blockers) are unlikely to have an effect on the pharmacokinetic properties of eletriptan.

Eletriptan is not a substrate for MAO. Therefore there is no expectation of an interaction between eletriptan and MAO inhibitors. Therefore no formal interaction study has been undertaken.

In clinical studies with propranolol (160 mg), verapamil (480 mg) and fluconazole (100 mg) the C_max of eletriptan was increased 1.1 fold, 2.2 fold and 1.4 fold respectively. The increase in eletriptan’s AUC being 1.3 fold, 2.7 fold and 2.0 fold respectively. These effects are not considered clinically significant as there were no associated increases in blood pressure or adverse events compared to administering eletriptan alone.

In clinical studies with erythromycin (1000 mg) and ketoconazole (400 mg), specific and potent inhibitors of CYP3A4, significant increases in eletriptan C_max (2 and 2.7-fold) and AUC (3.6 and 5.9-fold) respectively, were observed. This increased exposure was associated with an increase in eletriptan t_1/2 from 4.6 to 7.1 hours for erythromycin and from 4.8 to 8.3 hours for ketoconazole (see section 5.2). Therefore, RELPAX should not be used together with potent CYP3A4 inhibitors e.g., ketoconazole, itraconazole, erythromycin, clarithromycin, josamycin and protease inhibitors (ritonavir, indinavir and nelfinavir).

In clinical studies with oral (caffeine/ergotamine) administered 1 and 2 hours after eletriptan, minor though additive increases in blood pressure were observed which are predictable based on the pharmacology of the two drugs. Therefore it is recommended that either ergotamine-containing or ergot-type medications (e.g., dihydroergotamine) should not be taken within 24 hours of eletriptan dosing. Conversely, at least 24 hours should elapse after the administration of an ergotamine-containing preparation before eletriptan is given.

Effect of eletriptan on other medicinal products

There is no in vitro or in vivo evidence that clinical doses (and associated concentrations) of eletriptan will inhibit or induce cytochrome P450 enzymes including CYP3A4 drug metabolising enzymes and therefore it is considered that eletriptan is unlikely to cause clinically important drug interactions mediated by these enzymes.

Selective Serotonin Reuptake Inhibitors (SSRIs)/Serotonin Norepinephrine Reuptake Inhibitors (SNRIs) and Serotonin Syndrome

There have been reports describing patients with symptoms compatible with serotonin syndrome (including altered mental status, autonomic instability and neuromuscular abnormalities) following the use of selective serotonin reuptake inhibitors (SSRIs) or serotonin noradrenaline reuptake inhibitors (SNRIs) and triptans (see section 4.4).

Pregnancy

For RELPAX no clinical data on exposed pregnancies are available. Animal studies do not indicate direct or indirect harmful effects with respect to pregnancy, embryonal/fetal development, parturition or postnatal development. RELPAX should be used during pregnancy only if clearly needed.

Breast-feeding

Eletriptan is excreted in human breast milk. In one study of 8 women given a single dose of 80 mg, the mean total amount of eletriptan in breast milk over 24 hours in this group was 0.02% of the dose. Nevertheless, caution should be exercised when considering the administration of RELPAX to women who are breast-feeding. Infant exposure can be minimised by avoiding breast-feeding for 24 hours after treatment.

RELPAX has moderate influence on the ability to drive and use machines. Migraine or treatment with RELPAX may cause drowsiness or dizziness in some patients. Patients should be advised to evaluate their ability to perform complex tasks such as driving during migraine attacks and following administration of RELPAX.

Summary of the safety profile

RELPAX has been administered in clinical trials to over 5000 subjects, taking one or two doses of RELPAX 20 or 40 or 80 mg. The most common adverse reactions noted were asthenia, somnolence, nausea and dizziness. In randomised clinical studies using doses of 20, 40 and 80 mg, a trend for a dose-dependency of the incidence of adverse events has been shown.

Tabulated list of adverse reactions

The following adverse reactions (with an incidence ≥1% and higher than placebo) were reported in patients treated with therapeutic doses in clinical trials. Events are categorized by frequency as common (≥1/100 to <1/10), uncommon (≥1/1,000 to <1/100), or rare (≥1/10,000 to <1/1,000).

The common adverse events seen with eletriptan are typical of adverse events reported with 5-HT1 agonists as a class.

In post-marketing experience, the following undesirable effects have been reported:

Immune system disorders: allergic reactions, some of which may be serious, including angioedema

Nervous system disorders: serotonin syndrome, rare cases of syncope, cerebrovascular accident

Vascular disorders: hypertension

Cardiac disorders: myocardial ischaemia or infarction, arteriospasm coronary

Gastrointestinal disorders: as with some other 5HT 1B/1D agonists, rare reports of ischaemic colitis have been received, vomiting.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

Not applicable.