A 25-year-old healthy woman used patches for transdermal release of scopolamine (Scopoderm) for pre

Fråga: A 25-year-old healthy woman used patches for transdermal release of scopolamine (Scopoderm) for prevention of motion sickness for the first time during a boat trip. The trip lasted for approximately two weeks and during this time she took one patch every 72 hours. She tried to stop the treatment but experienced nausea, vomiting and tachycardia within 12 hours after removal of the patch, which forced her to continue the therapy. However, after another three weeks she was able to gradually reduce the dose to one fourth of an ordinary patch but cannot completely stop the treatment. Has this reaction been described before and how can it be managed?

Sammanfattning: Withdrawal symptoms, including nausea, vomiting and dizziness have been reported to occur after finishing preventive treatment with transdermally released scopolamine for motion sickness. The reaction seems to be rare and the incidence might increase with the duration of therapy. A gradual decrease of the administered dose is recommended or the use of another antiemetic drug to treat the symptoms.

Svar: Scopolamine is a quaternary alkaloid with anticholinergic properties that is licensed for use in the prevention of motion sickness. Scopolamine passes the blood-brain barrier and is said to have prominent effects at low therapeutic doses. The mechanism of action when used in preventing motion sickness is not fully known but is probably mediated through an effect on the cortex or more peripherally on the vestibular apparatus (1).

The transderm scopolamine system consists of a thin film with a scopolamine reservoir and a polypropylene membrane that controls the rate of delivery of scopolamine. The patch remains in place behind an ear for 72 hours. The amount of scopolamine that is released is directly proportional to the area of the patch. After removing the patch, excretion continues for about 12 hours (2) and a considerable amount of scopolamine is excreted in the urine for the next two days (3).

A scopolamine withdrawal syndrome has been described earlier in the literature (3-5). Dizziness and nausea within 24-48 hours after removal of the patch have been reported in several patients. One patient also had a general feeling of illness and marked fatigue (5), another woman described intermittent sweating and paresthesias of the hands and feet (4). The symptoms have been reported to last for up to five days.

The Swedish Adverse Drug Reactions Advisory Committee (SADRAC) has received a single report of an 80-year-old woman suffering from Meniere´s disease who experienced pronounced withdrawal symptoms after stopping a 5-month-long course of transdermal scopolamine therapy.

The explanation for this withdrawal reaction is not clear but it has been proposed that it may be caused by a rebound effect due to treatment-induced adaptive changes. The symptoms are consistent with a mild cholinergic syndrome caused by an increase in the muscarinic receptor population and the resultant supersensitivity to endogenous acetylcholine (4).

In (6) it is stated that these withdrawal symptoms have occurred most often in patients who have used the transdermal scopolamine system for more than three days. Packages of the system in the United States contain a patient´s leaflet describing these symptoms.

The manufacturer (7) recommends to further lower the dose by cutting the plaster in smaller pieces or to use some other antiemetic drug during this troublesome period of withdrawal symptoms.

We suggest that the present case should be reported to SADRAC.