Discontinue use if syncope occurs. Lightheadedness can occur, especially during the 1st days of therapy. Correct intravascular vol- or Na-depletion (eg, in patients treated vigorously w/ diuretics) prior to administration. Inadequate fluid intake, excessive perspiration, diarrhea, or vomiting can lead to excessive fall in BP. Not to be taken w/ K supplements or K-containing salt substitutes. Not recommended in patients w/ severe hepatic impairment. Patients w/ biliary obstructive disorders or hepatic impairment. Discontinue use as soon as pregnancy is detected. Discontinue breastfeeding or discontinue the drug during lactation, taking into account the importance of therapy to the mother. Hydrochlorothiazide: Hypersensitivity reactions may occur in patients w/ or w/o history of allergy or bronchial asthma. Discontinue use before carrying out tests for parathyroid function. Risk of exacerbation or activation of SLE; hyperuricemia, frank gout; hyperglycemia; increases in cholesterol & triglycerides; non-melanoma skin cancer. Perform periodic determinations of serum electrolytes at appropriate intervals. Observe for clinical signs of fluid or electrolyte imbalance eg, hyponatremia, hypochloremic alkalosis, & hypokalemia. Regularly check skin for any new lesions & promptly report any suspicious skin lesions. Limit exposure to sunlight & UV rays. Not to be given w/ lithium. May precipitate azotemia in renal disease. Patients w/ progressive liver disease or severe renal disease. Telmisartan: Oliguria &/or progressive azotemia & (rarely) w/ acute renal failure &/or death in patients whose renal function may depend on activity of the renin-angiotensin-aldosterone system (RAAS) eg, patients w/ severe CHF. Anticipate increases in serum creatinine or BUN in patients w/ unilateral or bilateral renal artery stenosis. Closely monitor renal function in dual blockade of the RAAS eg, by adding ACE inhibitor. Not recommended in concomitant use w/ ramipril.