How long should i use oxybutynin chloride 5mg for hyperhidrosis? the doctor asked me to use it twice a day to reduce excessive sweating mainly the scalp and forehead?

Unfortunately, continued treatment is necessary to maintain the response to treatment. Systemic therapy with oral medication such as oxybutynin (an anticholinergic agent) is usually less satisfactory due to side effects (dried mouth, blurred vision, headache and urine retention). Furthermore, the long-term efficacy and safety of anticholinergic drugs when utilized for this indication.

Ask your doctor for alternative treatment