Cyclizine lactate prevention of postoperative nausea and vomiting

Approved indication: prevention of postoperative nausea and vomiting
Valoid (Link Medical Products)
ampoules containing 50 mg/1 mL for injection
Australian Medicines Handbook section 1.2.1

About a third of patients will develop postoperative nausea and vomiting if they are not given prophylaxis. It is more common in women, especially after abdominal surgery.

Cyclizine, an antihistamine, is already being used (tablets and injectable solution) as an antiemetic after surgery in Australia. However, the solution for injection has only recently been approved by the Therapeutic Goods Administration.

A Cochrane review of antiemetics analysed 10 studies of parenteral cyclizine.¹ The trials were mainly in women having surgery (caesarean, laparoscopy), except for one study in boys. An analysis of these studies found that cyclizine decreased the risk of nausea by 65% and vomiting by 55%, compared to placebo. Overall, cyclizine’s antiemetic effect was comparable to ondansetron. However in the study of boys having surgery for hypospadias, cyclizine was no better than placebo.²

In a trial not included in the review, cyclizine was compared to droperidol in patients administering their own analgesia after surgery. Thirty women were randomised to receive cyclizine or droperidol during surgery and then after, intravenously, with patient-controlled morphine. Nausea scores were comparable between treatments, with three patients in each group needing extra antiemetics.³

Cyclizine has also been used in combination with other antiemetics. Before anaesthesia, 960 women undergoing day surgery were given intravenous cyclizine 50 mg, intravenous granisetron 1 mg, or both. Postoperative nausea and vomiting were less common with combination treatment than with cyclizine or granisetron alone (17% vs 23% and 24%).⁴

Cyclizine’s antiemetic effect lasts for approximately four hours. The elimination half-life is around 14 hours following a single 25 mg intravenous dose. Cyclizine can be given up to three times a day but treatment should not continue beyond 48 hours.

Drowsiness is common with cyclizine and it may have additive effects with alcohol and other drugs that cause nervous system depression such as hypnotics, sedatives and anaesthetics. Other adverse effects include dizziness, dry mouth, constipation, blurred vision, headache, somnolence, dyskinesia, tremor, convulsions, transient speech disorders and injection-site reactions. Disorientation, restlessness, agitation, insomnia and hallucinations have also been reported. Temporary paralysis has occasionally occurred in patients with underlying neuromuscular disorders.

Because of its anticholinergic effects, cyclizine may precipitate urinary retention and incipient glaucoma. Monitoring is recommended in patients with glaucoma, obstructive disease of the intestine, liver disease, epilepsy and prostatic hypertrophy. As cyclizine may cause thickening of bronchial secretions, it should be used with caution in patients with asthma or chronic obstructive pulmonary disease. This drug may increase the adverse effects of other anticholinergic drugs.

Cyclizine is contraindicated in patients with severe heart failure. It is a category B3 drug and its use in pregnancy and lactation is not recommended.

This drug is effective for preventing postoperative nausea and vomiting, and is comparable to other antiemetics such as ondansetron, granisetron and droperidol. Cyclizine is not recommended for children and there have been no studies in older people.

🅃 manufacturer provided the product information

The Transparency Score is explained in New drugs: transparency, Vol 37 No 1, Aust Prescr 2014;37:27.

At the time the comment was prepared, information about this drug was available on the websites of the Food and Drug Administration in the USA and the European Medicines Agency.

Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.