Nadroparin (Fraxodi® en Fraxiparine®) is a low molecular weight heparin, and is used for treatment and prophylaxis of thrombo-embolic disorders. Headache is a very common complaint with variable etiologies, such as tension type headache and migraine.
Headache is not mentioned in the Dutch SmPC of nadroparin. The Netherlands Pharmacovigilance Centre Lareb received fourteen reports of headache or migraine associated to the use of nadroparin. The reported latency varied between 20 minutes and 3 days. In the majority if the cases (n=9), headache occurred in within hours after administration of nadroparin. In at last ten patients, the symptoms resolved after withdrawal of nadroparin. Six patients reported recurrence of headache after following administrations of nadroparin. This strong time relationship in our reports suggest a causal relation between the adverse events and the use of nadroparin. The association is supported with a possible pharmacological mechanism of vasodilatation induced by heparins by NO (nitric oxide) release, causing headache. Further investigation is warranted to confirm this possible adverse drug reaction.