The combination drug Afaris FC 300/150 commonly contains rifampicin (300 mg) and isoniazid (150 mg), and is used for the treatment of tuberculosis. Like other anti-tuberculous medications, it can cause a range of side effects, some of which may be serious and require prompt medical attention[7].
- Common side effects include nausea, vomiting, diarrhea, upset stomach, loss of appetite, and changes in urine color (orange or red urine, sweat, saliva, or tears, which is harmless but can stain contact lenses)[1][3][8].
- Liver problems: Liver function should be checked before and during treatment. Symptoms such as yellow eyes or skin (jaundice), dark urine, severe pain in the gut or upper abdomen can indicate serious liver injury. If liver problems develop, treatment should be stopped immediately[2][7].
- Nervous system effects: Numbness, tingling, burning, or pain in the hands and feet, dizziness, confusion, seizures, agitation, and rarely, severe mood changes. Vitamin B6 is often given with isoniazid to reduce the risk of neuropathy in susceptible patients[2][7].
- Respiratory issues: Trouble breathing, chest pain, cough, interstitial lung disease, pneumonitis, and pulmonary fibrosis are possible adverse effects. These require urgent medical attention[7].
- Allergic reactions: Skin rash, itching, swelling, hives, difficulty breathing, and swelling of the face, lips, or tongue may occur. Immediate medical help should be sought if these symptoms present[7][8].
- Gastrointestinal symptoms: Constipation, stomach discomfort, loss of appetite, dry mouth, and occasionally severe pain due to pancreatitis[3][7].
- Blood and metabolic effects: Diabetes control may become difficult, increased blood sugar, anemia, increased thirst, and more frequent urination[2][3].
- Musculskeletal issues: Joint pain, muscle and bone pain, swelling, and bone pain may be experienced[3][7].
- Ocular effects: Periodic eye examination is suggested during treatment to check for blurred vision or changes in color vision[2][7].
- Other effects: Fatigue, headache, fever, chills, irregular periods, acne, and breast enlargement in men have also been noted[3][7].
Special warnings: Patients with pre-existing liver disease, diabetes, renal impairment, history of gout, or neuropathy require special monitoring. Alcoholic patients and those predisposed to neuropathy should use the drug cautiously and under close supervision. Treatment should be discontinued if severe side effects develop[2].