Side Effects

Olmesartan:
Dizziness, itching, skin rash, difficulty in breathing or swallowing.
Hydrochlorothiazide
Volume depletion and electrolyte imbalance (especially hyperkalaemia); dry mouth, thirst; lethargy, drowsiness; muscle pain and cramps; rashes, photosensitivity, thrombocytopenia, jaundice, pancreatitis; fatigue, weakness; may precipitate an attack of gout; impotence; hyperglycaemia; anorexia, nausea, vomiting, constipation, diarrhoea; sialdenitis; raised urinary calcium concentration; headache, dizziness; back pain, myalgia; first-dose hypotension; angiodema; neutropenia; GI disturbances; transient elevation of liver enzymes; taste disturbances, cough; exacerbation or activation of systemic lupus erythematous; palpitations; xanthopsia; leucopenia, agranulocytosis, aplastic anaemia; necrotising angiitis; glucosuria; renal dysfunction, interstitial nephritis, renal failure; migraine; hyponatraemia; UTI; chest pain; gastritis, wt gain, dyspepsia, abdominal pain; bronchitis, upper respiratory infection, nasal congestion, sinusitis; rise in cholesterol and/or triglycerides.
Potentially Fatal: Hypersensitivity reactions; hemolytic anaemia; toxic epidermal necrolysis.