Pharmacokinetics and Pharmacodynamics

Pharmacokinetics and Pharmacodynamics: Oral Contraceptives
Oral contraceptives (birth control pills) are one of the most commonly-prescribed medications for women. In the United States, approximately 25% of women age 15-44 use some form of hormonal contraceptives (Cooper, 2017). But just like the decision to use birth control itself is highly individualized, pharmacodynamic factors such as age and health status can impact the patient’s response to birth control pills and patients must be carefully monitored throughout the duration of their lives to ensure that their form of birth control suits their lifestyle needs and the changes in their bodies over time. As noted by Cooper (2017): three types of oral contraceptive pills currently exist, that of combined estrogen-progesterone pills, progesterone only pills and the continuous or extended use pill. The most commonly-prescribed pill is that of the combined estrogen-progesterone combination.
The actual pharmacokinetics of birth control pills is achieved through the regulation of estrogen and progesterone. Progesterone prevents ovulation by providing negative feedback to prevent “the pulse frequency of gonadotropin releasing hormone.  This, in turn, will decrease the secretion of follicle- stimulating hormone (FSH) and decreases the secretion of luteinizing hormone (LH)” (Cooper, 2017, par.2). Progesterone also makes cervical mucous “unfriendly” to sperm implantation (Cooper, 2017, par.2). But while the basic mechanism of birth control pills may be fairly consistent, not all women react the same to taking contraceptives. Also, different health complaints can influence the degree to which oral contraceptives are appropriate for use in pregnancy.
Oral contraceptives have many advantages for women. Unlike a diaphragm, they do not require adherence to a specific method of insertion to prevent pregnancy (and diaphragms must remain inserted six hours after intercourse to remain effective). They also do not have the physical awkwardness some women experience with IUD insertion. Hypertension can contraindicate women from using any type of oral contraceptive and in the case of my patient, a combination of hypertension, diabetes, and smoking, had led to a reliance upon barrier methods of birth control in the form of condoms. Smokers like the patient over the age of 35 are also contraindicated from using oral contraceptives, due to evidence-based research indicating that they are at high risk for significant cardiovascular events and deep vein thrombosis (Cooper, 2017). Other contraindications include heart disease, migraines, or a history of breast cancer (Cooper, 2017).
After initiating a monogamous relationship with a man, the patient indicated she had quit smoking in the hopes of going on oral contraceptives. Her hypertension and diabetes were also under control. This made the use of hormonal contraceptives less risky from the perspective of a cost-benefit analysis. Previously, women over the age of 35 were not prescribed birth control pills, regardless of health status, but today the amount of estrogen in pills is significantly reduced, versus previous forms of the pill (Utian, 2018). The reduced risk of endometrial, ovarian, and colon cancer among women using combined pills has likewise made prescribing the drug to older women more popular (Utian, 2018). But women can still experience side effects such as nausea, breakthrough bleeding, and headaches. Trying different formulas may be necessary before the patient determines what specific type of pill is best suited for her body.
Lifestyle factors, can influence the suitability of method as well as physiological response. Combined pills are most effective when taken at the same time of day and the patient must remember to take the pill every day (Cooper, 2017). The chaotic lifestyle of the patient, combined with her uncertainty about adhering to diet and exercise to keep her hypertension and diabetes fully controlled eventually resulted in a determination that birth control pills would likely not be the optimal choice.

References
Cooper, D. (2017). Oral contraceptive pills. NCBI. Retrieved from:
https://www.ncbi.nlm.nih.gov/books/NBK430882/
Utian, W. (2018). Birth control pills and age. National Women's Health Resource Center, Inc.
Retrieved from: http://www.healthywomen.org/content/ask-expert/1778/birth-control- and-age