An alternate method of birth control is needed when taking antibiotics.-when the client is taking oral contraceptives and begins antibiotics, another method of birth control should be used. antibiotics decrease the effectiveness of oral contraceptives. approximately 510 pounds of weight gain is not unusual, so answer a is incorrect. if the client misses a birth control pill, she should be instructed to take the pill as soon as she remembers the pill. answer c is incorrect. if she misses two, she should take two; if she misses more than two, she should take the missed pills but use another method of birth control for the remainder of the cycle. answer d is incorrect because changes in menstrual flow are expected in clients using oral contraceptives. often these clients have lighter menses.