Breast cancer chemo is especiallly brutal. Not all cancer chemos are equal. I took a “chemo” drug for my ectopic pregnancy, a small dose, and there was no side effects for me. I did take Zofran at the same time, because I’m paranoid of feeling nauseas, but most people don’t bother or need the anti-nausea drugs. That same chemo drug is used for some autoimmune diseases.
The problem with lots of chemo drugs is to kill the cancer they also kill off good things in your body. Antibiotics do that too, some worse than others.
Statin drugs used to lower cholesterol can cause kidney problems in some people that lead to bad muscle pain, sometimes severely damaging muscles or death. I know one woman who was practically crippled by a statin, and another who died. I know many people who stopped the statin right away, or within a short time, when the pains started, and they are fine. I know other people who have no trouble at all.
Any medicine you’re highly allergic to would be bad for that individual. The worst side effect being death. You can die from any and all drugs if your allergy cause anaphylaxis or Steven-Johnson Syndrome. The latter is why drugs have warnings to contact your doctor if you develop a rash. If you get Steven-Johnson’s you typically wind up on the burn unit, because your skin begins to peal off, and patients die all too often once they come down with it. A lot of doctors are clueless about it. Anyone who has worked in a burn unit in a hospital can tell you about it.
@RedDeerGuy1 People complain about the metal taste with Flagyl (metronidazole). There are probably others. Some chemos leave a bad taste in the mouth too.