Active ingredients that have been commonly used in compound analgesics include: There is evidence that a compound of two analgesics with different mechanism of action can have an increased painkilling effect over the sum of the effect of each individual analgesic.
[1] Several such formulations have disappeared from over-the-counter status in drug store aisles and other retail outlets.
One example is APC (aspirin, phenacetin, and caffeine) compound tablets common from the 1940s to 1983; because of harmful side effects of phenacetin, Anacin in the U.S. was reformulated to eliminate it; while Vincent's APC is no longer sold.
Lenoltec is a compound analgesic that comes in four strengths: Another example is Bex, a once popular Australian compound analgesic which is no longer sold.
[2] The United States Food and Drug Administration also now requires that manufacturers of compound analgesics unequivocally state each ingredient's purpose.