Is it fair to say that pharmacotherapy (the use of pharmaceuticals to treat disease) is a subset of chemotherapy (the use of chemicals to treat disease)?

If not, why? Aside from the fact the former involves a subset of available chemicals and the latter all chemicals, what is the difference between the two?


2 Answers 2


I would like to believe that the major difference between these terms is based on their backgrounds and time however nowadays there are used interchangibly, without paying much attention to actual definitions.


The term chemotherapy was coined by Ehrlich at the beginning of the 20th century to describe the use of synthetic chemicals to destroy infective agents. In recent years, the definition of the term has been broadened to include antibiotics-substances produced by some microorganisms (or by pharmaceutical chemists) that kill or inhibit the growth of other microorganisms. It can also be broadened to include agents that kill or inhibit the growth of cancer cells.

Chemotherapy is the term originally used to describe the use of drugs that are 'selectively toxic' to invading microorganisms while having minimal effects on the host.

The term also embraces the use of drugs that target tumours and, in fact, has now come to be associated specifically with that branch of pharmacology (Oncology). Although, in the public mind at least, chemotherapy is usually associated with cytotoxic anticancer drugs that cause unwanted effects such as loss of hair, nausea and vomiting.

Pharmacotherapy is a more recent term which generally means the treatment of diseases through the administation of drugs. However there is more to it, the term also describes a more patient-focussed approach in which pharmacists treat patients through drug management with one or more specific outcomes.

The specific goals of pharmacotherapy (primary therapeutic outcomes include):

• Cure of disease (e.g., bacterial infection).

• Reduction or elimination of symptoms (e.g., pain from cancer).

• Arresting or slowing of the progression of disease (e.g., rheumatoid

arthritis, HIV infection).

• Preventing a disease or symptom (e.g., coronary heart disease).

Other important outcomes of pharmacotherapy include:

• Not complicating or aggravating other existing disease states.

• Avoiding or minimizing adverse effects of treatment.

• Providing cost-effective therapy.

• Maintaining the patient’s quality of life.

A systematic approach is consistently applied to each case. The steps involved in this approach include:

  1. Identifying real or potential drug therapy problems

  2. Determining the desired therapeutic outcome(s)

  3. Evaluating therapeutic alternatives

Hope this helps


  • RANG AND DALE’S Pharmacology 8th edition: Basic principles of antimicrobial chemotherapy

  • Pharmacotherapy Casebook


In common medical usage, chemotherapy refers specifically to treating cancer with drugs. Pharmacotherapy is a more general term that includes treating any disease with a chemical substance.

This is the customary way the terms are used which has arisen because that is how people use the terms. It might seem that chemotherapy should refer to any chemical used in treatment but that isn't how the terminology evolved. Language isn't always a rational thing.


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