Agonist and Antagonist
Psychopharmaceuticals are drugs that aim to target neurotransmission sites and its spectrum of agonist to antagonist is seen as its aftereffects. An agonist is a drug that attaches itself to the receptor, generating responses that are similar to the anticipated receptor or chemical. An antagonist, on the other hand, opposes the outcome of the agonist or stops a receptor from generating a response. Antagonists bind to the receptor producing slow responses or inhibiting responses altogether. Agonists usually imitate the activities of ordinary neurotransmitters like Acetylcholine, generating responses that are similar to the receptors they bind to (Gronich et al., 2018). Agonists promote drug action while antagonists inhibit drug action. Partial and Inverse Agonist Functionality and Psychopharmacologic Treatments Partial agonists have lower efficacy than a full agonist. A partial agonist produces sub-maximal triggers even when they occupy the entire receptor population. Partial agonists cannot produce a maximum response of a drug regardless of the concentration administered. An inverse agonist, on the other hand, binds to the same receptor as an agonist but provides the opposite effect to that of an agonist (Gronich et al., 2018). The main pharmacological effect of inverse agonists is to suppress spontaneous receptors. The Action of G Couple Proteins and Ion Gated Channels G couple proteins are abundant membrane proteins. An ion gated channel, on the other hand, is a channel that allows specific ion to pass through, ion channel and g protein is similar their linked receptors bind a ligand. G coupled receptors interact with various proteins for an intercellular response while ion gated channels control the flow of ions. G-proteins are activated by neurotransmitters or voltage which bid to a metabotropic receptor, this allows for therapeutic drug action to occur (Yudin & Rohacs, 2019). When activated, G-proteins dissociated from the receptor and mingle with ion channels or connect to other effector proteins that make intracellular messengers that function to close or open ion channels. Ion gated channels and g proteins are protein receptors embedded in cell membrane bind to a molecule, certain medications can change the flow of ions to cause a clinical effect. The Role of Epigenetics to Pharmacologic Action Epigenetics determines if some genes will become protein or RNA or it will be modified based on the environment, neurotransmission, chromatin, genes drugs. This can affect the brain and the way it processes information, and the risk of psych disorders can increase. The activity of epigenetics is important in maintaining the normal phenotypic activity of cells. Understanding epigenetics helps researchers understand the role of genes in the development of diseases and neurodegenerative disorders like Alzheimer’s disease (Stover et al., 2018). Epigenetics is important in pharmacology since it boosts the ability of pharmaceutical scientists to control human diseases through pharmacological means. Impact of Information on Medication Prescriptions Safety and efficacy should be a priority when prescribing medication. Understanding how different drugs impact pharmacological action in the body is important in drug prescription. Understanding a patient’s history with medications is important in order to know whether a patient will respond to certain medications (Yudin & Rohacs, 2019). An example of a case where a practitioner had to be aware of a medication’s action is that of a patient coming to the clinic complaining that the antidepressants given to treat her depression were not working symptoms are getting worse after a week on the medication. The patient in question was prescribed the SSRI (selective serotonin reuptake inhibitor), Sertraline. Not only should the target action and dosage instructions of the drug be explained to the patient, but the side effects, missing doses, and signs and symptoms one may experience when taking this medication, should also be explained. With a change, or increase or decrease in a prescribed medication, the Practitioner must make accommodations for follow-up as needed. The mechanism of Sertraline on the CNS, its actions or effects may be delayed, so this should also be explained to the patient. SSRIs work to increase serotonin and its associated receptors in the brain to improve mood, emotion, and sleep, and its safety is of utmost priority during prescription. Antidepressants are often prescribed to help treat depression symptoms and only one-third of the patient population benefit from them. Therefore, it is important for practitioners to understand how different medications work in order to find alternative medications for a mental health medical condition. For mental health conditions, understanding that some biomarkers may impact a patient’s healing process is important in understanding what medications and treatment procedures to prescribe to a patient.
Ehlert, F. (2015). Affinity and efficacy: the components of drug-receptor interactions. Singapore: World Scientific Publishing.
Stefanska, B. & MacEwan, D. (2015). Epigenetics and Pharmacology. British Journal of Pharmacology, 172(11), 2701-2704. https://dx.doi.org/10.1111/bph.13136
Stern, T. A., Favo, M., Wilens, T. E., & Rosenbaum, J. F. (Eds.) (2015). Massachusetts General Hospital Psychopharmacology and Neurotherapeutics. Elsevier.
Use them as references, please.
Why would we combine a partial agonist such as Buprenorphine with an antagonist such as Naloxone into a single medication like Suboxone? As you are probably aware, oral Naloxone has nearly 0% bioavailability when given orally. If none of the drugs is absorbed, why use them in the combination?
Naloxone is added to sublingual buprenorphine to prevent the intravenous abuse of buprenorphine. This is because when both drugs are taken combined as sublingual tablets, the opioid impact of buprenorphine takes precedence and prevents opioid withdrawal.
Yes, I am aware that Naloxone has minimal absorption when taken orally or sublingually. When administered as sublingual tablets, buprenorphine’s opioid effects surpass naloxone, effectively halting opioid withdrawals. Nevertheless, if the sublingual pills are broken and injected, naloxone dominates and can cause opioid withdrawal (Blazes & Morrow, 2020).
Blazes, C. K., & Morrow, J. D. (2020). Reconsidering the usefulness of adding naloxone to buprenorphine. Frontiers in Psychiatry, 11, 958.