One partner's low libido can be the downfall of a relationship. But if the cause is a medication, particularly one the partner needs for his or her health, then a couple can be in a tough situation. Here are some medications that can affect sex drive. Blood pressure problems can trickle down, so to speak, and become a major contributor to erectile dysfunction. Once blood pressure is lowered, it seems it would help the situation; however, many blood pressure meds can exacerbate ED. Talk to your doctor (or your partner's doctor) about certain families of blood pressure medications that actually help ED. Depression is another multi-faceted disease when it comes to sexual dysfunction. While the disease itself reduces libido, so can the medications that treat it, particularly a family of drugs called selective serotonin reuptake inhibitors, or SSRIs. It includes drugs like Prozac, Lexapro and Paxil, with which many people successfully treat depression.