Updated: Aug 9, 2020
Pharmacology as a subject,
is the scientific study of how drugs (chemical compounds) can interact with a myriad of receptors located in various tissues of the body to produce effects that change a physiological outcome in the body. For example, how does a drug work to decrease blood pressure?
There are many branches of pharmacology-i.e. clinical, molecular. Clinical pharmacology that explores the importance of toxicity and safety of drugs when they act at receptors. For instance, what is the effect of increasing the concentration of a drug? What does this do physiologically for the person affected?
Clinical pharmacology is utilized by many health professionals. Medical students require an understanding of how drugs work to produce their effects. They need an understanding of the side effects of drugs.
Pharmacy as a subject
students and pharmacists also require extensive knowledge in pharmacology: this serves as their core role in the healthcare team they are part of. They need to understand drug-drug interactions, which they learn from their pharmacology studies. Pharmacists will be more adept with their knowledge of pharmacology because they are specialists in the field of medicines.
Doctors will from time to time find it difficult to remember the tiny details and rely on the pharmacists for their advice on doses of medicines, adverse effects, and drug-drug, drug-disease and drug-food interactions.
People who study pharmacology can be those who are involved in research. They don't tend to study clinical pharmacology, which is essential for patient care. Rather, they study molecular pharmacology. They want to understand the science behind how drugs bind to receptors and what happens to "molecules", hence molecular. This has little relation to what happens to a patient in terms of side effects, doses and drug interactions. This field is important for scientists wishing to advance the pharmaceutical science profession: developing better drugs through understanding the science of how drugs bind and produce effects.
Pharmacists will also study other subjects that relate to patient care-they need to know about disease states: how drugs are useful in those disease states. They should know for instance what asthma is as a condition-this helps them in understanding and explaining the difference between two types of inhaled medications-salbutamol is a "reliever" medication used in an asthma attack because it opens up the airways (which are constricted in asthma) and budesonide is a steroidal medication which has effects that take time and hence prevent asthma attacks and don't help with the asthma attack (which is an emergency!).
In simple explanation is ‘Pharmacy is a profession while pharmacology is a subject’.