Carpine 0.5% Injection is used in the treatment of dry mouth after radiotherapy of head and neck cancer. It works by reducing abnormal dryness of the mouth which makes speaking and swallowing easier. Carpine 0.5% Injection must be administered by a healthcare professional in the hospital or in a clinical setting. You should not self administer this medicine at home. The most common side effects of this medicine are headache, sweating, frequent urge to urinate, and flu syndrome. If you experience such symptoms that persist or worsen, or any other symptoms which you think may be due to this medicine, inform your doctor. It is not advised to drive after using this injection as it may decrease your alertness and make you feel dizzy.