If pyrithioxin hydrochloride is taken for a long period of time, some patients may experience side effects such as skin, digestive system and other systemic abnormalities. 1. Skin: A small number of patients may experience skin damage such as rash, redness and swelling after long-term use. 2. Digestive system: A few patients may experience nausea, vomiting, diarrhea and other indigestion symptoms after long-term use. 3. Systemic symptoms: some patients may have decreased appetite, mental depression, fatigue, drug fever and other abnormal symptoms. In addition, patients who have allergic reaction to the drug are prohibited from taking it. And for pregnant women also need to be used with caution, because there is a possibility of causing fetal cleft lip in animal experiments. Pyrithioxin hydrochloride should be used under the guidance of a doctor, such as long-term use of the drug appeared obvious side effects, you can follow the doctor’s instructions to adjust the medication.