In simple terms,
Medicinal and Pharmaceutical chem-involves synthesis, design of Pharmaceutical ingredients
Pharmacology-involves the study of how a drug affects human body-- This does include lots of biology
Now, if you want to study medicine by itself (i.e., medical school), it will definitely include lots of biology, chem and biochem. Look it this way, you can't really treat patients without knowing how the human body works
You have an option of going through the research route. If this works for you, try doing lab rotation or for undergraduate research credits in an organic or medicinal Chemistry research labs and see if you like the idea of pursuing a research career.
P.S: Not all biochemistry labs do biology. Sometimes, they deal with more chemistry than biology side of it