A law firm goodrx olmesartan 20 mg RIO DE JANEIRO, Aug 9 (Reuters) - Brazil's state-controlledoil company Petroleo Brasileiro SA on Friday reportedsecond-quarter profit of 6.20 billion reais ($2.71 billion),reversing a year-earlier loss after an accounting rule changeallowed it to avoid $3.5 billion in non-cash, exchange-ratecharges.