Along with its needing effects, a drug may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your family doctor immediately if any of the following side effects was happen
More common
Clumsiness or unsteadiness; dark urine; loss of appetite; nausea and vomiting; numbness, tingling, burning, or pain in hands and feet; unusual tiredness or weakness; yellow eyes or skin
Less common
Chills; difficulty in breathing; dizziness; fever; headache; itching; muscle and bone pain; pain in large and small joints; redness of skin; shivering; skin rash
Rare
Bloody or cloudy urine; blurred vision or loss of vision, with or without eye pain; convulsions - seizures; greatly decreased frequency of urination or amount of urine; mental depression; mood or mental changes; sore throat; unusual bleeding or bruising
More common side effects may occur that usually don't needed medical attention. These side effects may go away during treat as your body adjusts to the drug. However, check with your family doctor if any of the following side effects continue or are bothersome.
More Common
Diarrhea; stomach pain
Less common
Sore mouth or tongue
This drug commonly causes urine, stool, saliva, sputum, sweat and tears to turn reddish-orange to reddish-brown. This side effect does not usually require medical attention.
Dark urine and yellowing of the eyes or skin - signs of liver problems causing by isoniazid are more likely to occur in diseaseds 50 years of age and older.
More common side effects not listed above may also occur in some diseaseds. If you notice any other effects, check with your family doctor.