Medicines & Supplements A to Z > Benzhexol

Benzhexol

Last updated on 13/07/2021.

Overview   |   Dosage   |    Side Effects   |   Precautions   |   Tips   |   Where To Buy  

GENERIC NAME: Benzhexol

ALTERNATIVE NAME: Trihexyphenidyl

CHINESE NAME: 苯海索

BRAND NAME(S) IN HONG KONG: /

DRUG CLASS: Antiparkinsonian agents

SUB CLASS: Anticholinergics

USED FOR: Parkinson’s disease, Drug-induced extrapyramidal symptoms

AVAILABLE DOSAGE FORMS:
– 2mg (tablets)

What is Benzhexol for?

Benzhexol belongs to a class of medication called anticholinergics. It can regulate the nervous system to relax muscles and control movements to relieve the symptoms of parkinson’s disease and drug-induced extrapyramidal symptoms.

How to use it?

Benzhexol is taken orally as tablets. Doses ≥10 mg/day should be divided into 4 doses.

For Parkinson’s disease (monotherapy):
Initial: 1 mg once daily, and can be increased in 2 mg increments at intervals of 3-5 days.
Usual maintenance dose: 6-10 mg in 3-4 divided doses.

For Parkinson’s disease (combination therapy):
If used concomitantly with other drugs for Parkinson’s disease, for example Levodopa, the usual dose of each may need to be reduced.
Usual maintenance dose of Benzhexol: 3-6 mg/day in divided doses.

For drug-induced extrapyramidal symptoms (dystonia and parkinsonism):
Initial: 1 mg once daily.
Usual maintenance dose: 5-15 mg/day in 3-4 divided doses.

What are the side effects of Benzhexol?

Common side effects of Benzhexol include nausea, dry mouth, nervousness, weakness, tachycardia, dizziness, and headache. 

Who should not take Benzhexol?

– People who are allergic to Benzhexol or any component of the formulation
– Patients with narrow angle glaucoma
– Not recommended for elderly patients (e.g. >70 years old), and patients with dementia

Pharmacist Tips:

– Avoid driving or operating machinery until you know how you respond to Benzhexol as it may cause drowsiness.
– Avoid drinking alcohol during the treatment.
– Do not stop taking Benzhexol suddenly as it can cause withdrawal symptoms.
– This drug may affect your body’s heat regulation. Be careful in hot weather and during physical activity.

Common dosing schedule:
Generally, patients tolerate best if given in 3 daily doses with food. High doses (≥10 mg/day) may be divided into 4 doses at each meal and at bedtime.

If patients develop excessive dry mouth, consider administering before meals unless it causes nausea. For postencephalitic patients, who are usually more prone to excessive salivation, may prefer to take it after meals.

This schedule is for reference only, adjustments may be made according to individual needs.

Some common medications Benzhexol may interact with:
– Phenobarbital
– Anticholinergics, e.g. Ipratropium, Tiotropium
– Potassium, e.g. Potassium chloride, Potassium citrate
– Opioids, e.g. Tramadol, Codeine, Fentanyl
– Tricyclic antidepressants, e.g. Amitriptyline, Imipramine, Doxepin

Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.

Where to buy Benzhexol in Hong Kong?

In Hong Kong, Benzhexol is a prescription only medicine, and requires a prescription from a doctor to be purchased in a pharmacy. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.

For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at https://www.drugoffice.gov.hk

Need more information?

For detailed information about the use of Benzhexol in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.