OCD treatment requires high doses of medication and long dosing times. Some medications can cause drowsiness and fatigue; some can cause nausea and vomiting; some can cause panic, fidgeting, and dizziness. How to reduce the occurrence of adverse reactions? May be according to the following methods: 1, priority grade principle: First of all, choose SSRI drugs with small side effects, such as fluvoxamine, fluoxetine, sertraline, escitalopram, etc., must be sufficient dose (fluvoxamine generally need to take 100-300mg/day, can be divided into two doses, sertraline 100-200mg), a full course of treatment (4-15 weeks) is not effective. It can be replaced or combined with ‘clomipramine’, or add a small amount of ‘aripiprazole’. Consolidation of treatment is required for one year or more after improvement. 2.Early single medication: A single medication should be used at the beginning, which will reduce drug side effects. When a drug is not effective in full dose and full course of treatment, change to another, generally the better effect is clomipramine but its side effects are relatively larger than sertraline and other drugs. 3, the principle of individualized dose: all OCD patients, different people take different types of drugs, doses, not just according to the drug instructions to take, because sometimes there may be insufficient or too large a dose, affecting the efficacy of drugs. 4, slowly increase the amount of drugs: the beginning of the dose should be small, and then gradually increase the amount, 2-4 weeks to reach the amount of treatment, which will increase the patient’s adaptation to the drug, reducing the appearance of adverse reactions. 5, the standardized method of administration: In addition to the dose varies from person to person, the method and time of taking the drug should also be noted, if the morning dizziness, drowsiness, can be placed in the evening. If you take the drug on an empty stomach, stomach discomfort, can be placed in the meal or taken after the meal. Can reduce adverse drug reactions, but also to increase the bioavailability of some drugs, such as sertraline. 6, reasonable combination of drugs: If a single drug insomnia, anxiety, fidgeting can be a short-term combination of clonazepam. If a single drug in full dose, a full course of treatment is still ineffective, and also ineffective after a drug change, two or more drugs can be used in combination: clomipramine plus SSRI class, escitalopram plus clomipramine, or combined with aripiprazole, olanzapine to have effect. Or tretinoin plus clomipramine, sertraline plus aripiprazole plus clonazepam, some patients can also add sodium valproate treatment. 7, symptomatic treatment principles: Some drugs work well, but the appearance of excessive sweating, can use a small amount of benztropine, Saigeng, mirtazapine to relieve excessive sweating. Some drugs affect sexual function, you can choose to stop the drug once a week, you can also add buspirone, bupropion, etc. to improve the sexual function of patients.