Pharmacotherapy

Today's pharmacological therapy has evolved from a long history of medication use, and it has changed most rapidly in the last century due to advancements in drug discovery.

The therapy is administered and adjusted by healthcare professionals according to the evidence-based guidelines and the patient's health condition.

[6] Besides substances derived from living organisms, metals, including copper, mercury, and antimony, were also used as medical therapies.

[7] However, due to the concern over acute and chronic antimony poisoning, the role of tartar emetic as an antischistosomal agent was gradually replaced after the advent of praziquantel.

[5] Later in the 2nd century AD, compounding was formally introduced by Galen as “a process of mixing two or more medicines to meet the individual needs of a patient”.

[5] Initially, compounding was only done by individual pharmacists, but in the post-World War II period, pharmaceutical manufacturers surged in number and took over the role of making medicine.

[3] Most drug discovery milestones were made in the last hundred years, from antibiotics to biologics,[5] contributing to the foundation of current pharmacological therapy.

The substance was discovered by Alexander Fleming in 1928 after a combination of unanticipated events occurred in his laboratory during his summer vacation.

[8] The Penicillium mold on the petri dish was believed to secrete a substance (later named "penicillin") that inhibited bacterial growth.

[9] The screening program for antimicrobial compounds also led to the discovery of drugs with other pharmacological properties, such as immunosuppressants like Cyclosporin A.

The method is underpinned by an understanding of the biological targets of the drugs, including enzymes, receptors, and other proteins.

In the late 19th century, Paul Ehrlich observed the selective affinity of dyes for different tissues and proposed the existence of chemoreceptors in our bodies.

[9] Once the ligand interacting with the target macromolecule is identified, drug candidates can be designed and optimized based on the structure-activity relationship.

[11] Evidence-based medicine is defined as deploying the best current scientific evidence that is available to give the best treatment and make the best decision effectively and efficiently.

According to the NICE 2019 Hypertension guideline, the healthcare professional can consider starting anti-hypertensive therapy after a discussion with the patient.

The genetic variations can also be used to match the particular adverse drug reaction in order to prevent the patient from suffering the unfavorable outcomes.

Indirect method refers to the healthcare professionals do not observe or measure the drug-taking behavior of the patient but use the other source of information to evaluate the compliance.

[28] Apart from the traditional direct observed therapy (DOT), there is another method proposed to try increasing medication compliance.

As pharmacotherapy specialists and pharmacists have responsibility for direct patient care, often functioning as a member of a multidisciplinary team, and acting as the primary source of drug-related information for other healthcare professionals.

Image of latex sap from a poppy plant. Opium is extracted from latex sap.
Penicillin chemical structure
The drug-receptor recognition involves a "key", which is a ligand such as a drug, and a "lock", which is a receptor.
Summary of pharmacokinetics and pharmacodynamics