Sumatriptan
QUESTION
1. Drug pharmacology, pharmacokinetics
2. Brand name
3. Generic name
4. Dosing
5. Indications for use
6. Side effects
7. Contraindications
8. Pregnancy class
9. Cost analysis of the drug.
10. Provide a patient case study on a patient in which you would utilize sumatriptan and include at least two peer-reviewed evidence-based studies related to the drug.
11. Describe the appropriate patient education.
12. What is your role as a Nurse Practitioner in prescribing this medication
13. Describe the monitoring and follow-up.
Sumatriptan
ANSWER
Sumatriptan is in a class of drugs called triptans or selective serotonin receptor agonists (NHS, 2019). It works by constricting cranial blood vessels, blocking the release of neuropeptides that cause inflammation, and blocking the release of certain substances that cause pain, nausea, and other symptoms of migraines.
Sumatriptan is an agonist of 5-HT1B and 5-HT1D that leads to the narrowing of cranial blood vessels and inhibition of inflammatory peptides. Sumatriptan decreases blood flow to the carotid artery but increases the velocity in the internal carotid artery and middle cerebral artery. A migraine causes blood vessels in the brain to expand and releases chemicals responsible for nausea, swelling, and irritation (NHS, 2019). Sumatriptan works by negating the symptoms caused by migraines
The pharmacokinetics differs depending on the route of administration.
Absorption
A 6mg subcutaneous injection reaches a maximum serum concentration of 69.5 ng/ml, which translates to 95% within twenty minutes of administration (“Sumatriptan,” 2022). It has a bioavailability of 100%.
A 25mg oral dose reaches a maximum serum concentration of 16.5ng/ml, which translates to 95% within an hour and a half of administration (“Sumatriptan,” 2022). It also has a bioavailability of 14.3%.
A 20mg nasal spray reaches a maximum serum concentration of 12.9 ng/ml, which translates to 15.8%. It also has a bioavailability of 15.8%.
The volume of distribution: Sumatriptan has a volume of distribution of 2.4L/kg.
Protein binding: Sumatriptan binds to proteins by 14-21% in circulation.
Metabolism: Sumatriptan is metabolized by hepatic monoamine oxidase A isoenzyme to release its main metabolites; inactive indole acetic acid and indole acetic acid glucuronide.
Elimination route: Approximately 22% of Sumatriptan is excreted in the urine as unchanged Sumatriptan, approximately 38% as indole acetic acid in the urine, and approximately 40% of Sumatriptan is excreted through feces.
Half-life: Subcutaneous Sumatriptan has a half-life of 1.9h, oral 1.7h, and nasal 1.8h.
Clearance: Intravenous Sumatriptan has a clearance of 0.22L/min, oral 0.17L/min, and intranasal 0.21L/min. Overall, total plasma clearance is roughly 1200ml/min.
Pharmacogenomics effects: Researchers have directly studied Sumatriptan interaction with guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-3, genotypes (C; T) / (T; T), T allele and found that patients with this genotype have an increased likelihood of responding to Sumatriptan, especially when treating cluster headache.
Food interactions: Take Sumatriptan with food and water. When taken with Sumatriptan, chronic alcohol consumption increases the risk of gastrointestinal bleeding, ulcers, and perforations.
Toxicity: Toxicity may result in dizziness, fainting, slow heart rate, loss of bowel movement, and drowsiness. However, another incidence of a 36-year-old patient hat reported overuse of the injection with 66injections of 6mg taken within four weeks but with no adverse drug interactions observed physically or clinically.
Brand names
Imitrex, Embrace, Onzetra, Tosymra, Sumavel, and Treximet.
Generic name
Sumatriptan succinate
Dosing
Sumatriptan is available as a tablet indicated for migraines only, injection for migraines or cluster headaches, and a nasal spray for migraines or cluster headaches.
Tablet is available in strengths of 25mg, 50mg, and 100mg. The injectable solution is available in 6mg or 0.5 vials. The prefilled syringe cartridge is available in 3mg/0.5 mg auto-injector, 4mg, and 5mg forms.
migraines
Patients take the tablet as a whole without crushing or chewing. Additionally, a patient should not exceed 100mg per dose. However, if the migraine improves and then comes back, a patient is allowed to take the same dose again after two hours. If the first dose does not help, a patient is advised not to take the same medication for the same attack. Ultimately, the recommended maximum dose should not exceed 300mg/day.
An injection is available as an auto-injector in the strength of 6mg. If the first dose does not provide relief, a patient can repeat it after an hour of the first dose but should not exceed the overall dose of 12mg a day.
cluster headache
patients are expected to inject prefilled syringe that contains 6mg Sumatriptan directly into the thigh. It takes effect within ten to fifteen minutes. If the headache reduces and then comes back, the patient is expected to wait after an hour and inject another. If the first injection did not help, the patient should not repeat the same medication for a similar attack. The doctor might titrate a lower dose under certain circumstances, like when the patient experiences adverse reactions.
Dosage may also be modified when there is mild to moderate hepatic impairment, and the oral route takes the brunt, with the dosage slashed to 50mg/dose.
Indications for use
Sumatriptan is indicated for the treatment of migraines and cluster headaches. It is also FDA-approved to relieve photophobia and functional disability.
Sumatriptan is contraindicated in patients with severe hepatic impairment. It is also contraindicated for adults over sixty-five years. Children below twelve years are also not allowed to take the medication unless a specialist doctor prescribes it. Individuals with a history of coronary heart disease, angina, abnormal heart rhythm, and heart attack are also advised against it. Individuals with hypertension, peripheral heart disease, stroke, or seizures should also inform the doctor prior to prescription.
Additionally, pregnant patients who are trying to get pregnant or lactating patients should tell their doctor beforehand. Patients with known drug allergies should also inform the doctor before the prescription. The pharmacist or doctor should give an okay for those with latex allergies before administering the drug. St. Johns Wort is also contraindicated. After all, it risks increasing serotonin syndrome because it increases serotonin levels.
Pregnancy class
Animal studies have revealed several effects associated with lethality to the embryo, loss of fetal weight, increased pup mortality, decreased bone formation, and abnormalities of the skeletal tissue, with lethality to the embryo the most reported for doses that resulted in toxicity to the mother (Drugs.com, 2021). However, their results were only done on animal models, and there were no human pregnancy samples to serve as controls. The only data collected post-marketing on a thousand pregnant women was during the first trimester alone, and there were no patients that took it during the second or third trimester. The results were inconclusive, but there were no reports of fetal abnormalities.
In AU, TGA classifies Sumatriptan as pregnancy category B3 for drugs that have been taken by a limited number of women of childbearing age without evidence of harm to the fetus observed in animal samples (Drugs.com, 2021). The FDA classifies Sumatriptan as pregnancy category C for drugs that showed potential risks in animal studies in the US. However, the benefits far outweigh the potential risks associated with taking it. For these reasons, Sumatriptan is only given to pregnant women when the benefits outweigh the risks.
Breastfeeding warnings are that subcutaneous Sumatriptan injection is excreted into breast milk but has poor oral bioavailability, and thus amounts ingested by infants are small. However, the effects on infants are unknown (Drugs.com, 2021). Patients are thus encouraged to minimize infant exposure by breastfeeding eight to twelve hours after treatment with Sumatriptan.
Migraines have become one of the troublesome social diseases affecting close to 12% of the total world population. It is more common in individuals aged between thirty-five and forty years. Triptans are the best choice drugs for the treatment of migraines despite their higher cost and short relief times. Research conducted on the cost-effectiveness of selective 5HT1 receptor agonists in Ukraine found that the economic burden was on the consumer because the medication was effective yet short-lived.
Packaging with the same dose of the active ingredient with more tablets in the blister was more cost-effective compared to importing the same medication. (Hrynkiv et al., 2021) Additionally, it was more economical to use the 50mg packaging six tablets a blister during the dosage of Sumatriptan compared to any other doses. Value for a single tablet was calculated by finding the quotient of the cost of a single pack divided by the number of tablets. Using the quotients for all the brand names and dividing by the total number of brand names calculated the average cost for all the tablets.
According to the online drug database, the Imitrex syringe kit of 4mg and 6mg goes for 229.02 USD each, and the refill is roughly 216.92USD. Sumatriptan kit 6mg goes for 191.84USD and a refill of 4mg and 4mg for 184.46USD each (“Sumatriptan,” 2022). Imitrex 6mg vial goes for 106.84, and Imitrex 6mg solutions vial for 98.93USD. Imitrex nasal spray and inhaler range from 55.49USD- to 43.44USD. On average Imitrex 25mg, 50mg, and 100mg tablets go for 32.45, 30.16, and 30.16USD respectively. Sumatriptan 25mg, 50mg, and 100mg tablets go for 27.06, 26.15, and 26.15USD respectively. These figures depict Sumatriptan as superior in adherence to patients yet cheaper than its brand names.
Case study on patients under Sumatriptan
In a clinical trial where a placebo was used as a control, Sumatriptan administered orally, subcutaneously, and intranasally had better efficacy results than placebo in relieving migraine headaches and resolving symptoms associated with migraines like migraines dizziness, nausea, and pain (Lin et al., 2020). Additionally, the results also showed an improvement in clinical disability compared to placebo. Despite pain recurring in most care after the first dose, the second dose resolved the migraines.