This paper investigates how a combination of monetary and macroprudential policies might affect the dynamics of a small open economy (SOE) with financial frictions under alternative discretionary shocks. Discretionary shocks in productivity and domestic and foreign monetary policies identify the roles of alternative interest rate and reserve requirement rules to stabilize the economy. The model is calibrated for the Brazilian economy. The exchange rate channel of transmission is relevant for foreign but not for domestic shocks. The interest rate rule should target domestic inflation and should not react to the exchange rate. The countercyclical reserve requirements rule, in its turn, should aggressively react to the credit-gap and not include a fixed component. Under both domestic and foreign shocks, the countercyclical effectiveness of the macroprudential policy improves when the degree of openness increases. There is a complementarity between monetary and macroprudential policy rules to stabilize the SOE.