|You will also need to be tested for pregnancy in a laboratory each month during your treatment, when you take your last dose and 30 days after you take your last dose. The metabolism of Ibuprofen can be decreased when combined with Indinavir. Ultraviolet light seems to alter the chemical make-up of chloroquine in water. For example, 90 percent of Asians, 70 percent of blacks and Native Americans, and 50 percent of Hispanics are lactose intolerant, compared to only about 15 percent of people of Northern European descent. The risk or severity of adverse effects can be increased when Efavirenz is combined with Clopenthixol. Butabarbital: (Minor) Acetazolamide can induce osteomalacia in patients treated chronically with barbiturates.