About other prescription and nonprescription medicines, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Dolutegravir may affect the way other medicines or products work, and other medicines or products may affect how dolutegravir works. Taking dolutegravir together with certain medicines or products may cause serious side effects. Do not take dolutegravir if you take dofetilide. Taking dolutegravir and dofetilide can cause side effects that may be life threatening.