DiabetesMellitus Case Study
Thepathophysiology of paroxysmal supraventricular tachycardia
PSVTis characterized by an abnormally increased heart rate. Theyoriginate from a part of the heart that is just above the ventricles.PSVT occurs when the sinus node of the heart short circuits. Thefunction of the node is the transmission of electric signals toinstruct the heart muscles to contract (Ellis & Ross, 2015). Withreduced contractions, the heart beats faster than normal. PSVT canlast from minutes to several hours. It interferes with the normalheart function. It has uncomfortable symptoms on the patients.
Othermedications used for the treatment of PSVT
Fast-actingantiarrhythmic medicines may be administered in case of severesymptoms such as chest pains or loss of breath. These includebeta-blockers and Adenosine. Also, cardiac ablation is utilized toget rid of small regions of the heart that might be the cause of therapid heartbeats. The pacemakers come in handy in reducing fastheartbeat, and surgery helps to alter the paths in the heart transmitelectric signals.
Thepharmacodynamics of calcium channel blockers
Calciumchannel blockers dare useful in the treatment of hypertension andheart disease. They become efficient by decreasing blood pressure.They are as well employed in the treatment of angina by reducingchest pains. Verapamil helps in the treatment of migraines.
Howverapamil is different from other calcium channel blockers
Verapamilis different in that it has an additional side effect of slowing downthe heart rate. It relaxes the arteriolar smooth muscle, which leadsto the dilation of blood vessels. The effect leads to a reduction inperipheral resistance and arterial pressure. Verapamil also reducesthe myocardial contractions and AV conductions. The impacts may beenough to cause heart failure or blockage in the heart this is morelikely to happen if verapamil is administered with beta blockers.
Thepharmacokinetics of calcium channel blockers
Absorptionof the drugs takes place in the gut. However, their bioavailabilitydiffers depending on the degree of the first-class metabolism in theliver. Since metabolism slows down with age, the plasmaconcentration, bioavailability, and responses are more pronounced inolder people compared to younger people. The elimination half-livesalso differ with the drugs. Diltiazem and Verapamil have shorterones, allowing their administration to be possible even multipletimes in a day.
Thepharmacokinetics of verapamil
Thebody absorbs more than 90% of the oral dose. However, bioavailabilityis much lower due to the first-pass metabolism. The Optimal plasmaconcentrations occur between one and two hours following oraladministration. The liver metabolizes the drug to twelve metabolites.There is a non-linear relationship between Verapamil and verapamilplasma levels. The elimination half-life of the drug occurs between2.8 and 7.4 hours of administration (drugs.com, 2016). The half-lifeincreases to 4.5 to 12 hours after repeated doses. Age affects thepharmacokinetics of the drug. Older people exhibit higher eliminationof half-life.
Thepharmacotherapeutics of verapamil
Verapamilserves as an antiarrhythmic. It regulates the rate of ventricularcontractions in the vent of atrial fibrillation. It can also be usedprophylactically to treat repeated paroxysmal SVT. The oral form ofthe drug also helps in treating supraventricular tachyarrhythmias(Aschenbrenner & Venable, 2013). It is also suitable for thetreatment of angina and hypertension. It is also used in thetreatment of migraines.
Differentiatebetween the types of clinical use and related dosing of calciumchannelblockers
Verapamilrelaxes the arteriolar smooth muscle, which leads to the dilation ofblood vessels. Its dosage is 5 to 10 milligrams IV bolus for not lessthan two minutes for adults. The repeat dosage is 10 milligramsthirty minutes after the first dose if the patient does not respondadequately
Diltiazemis an arteriolar dilator. It minimizes peripheral resistance andhence the blood pressure. Even though it may lead to heart failure,it can be used with beta blockers to treat hypertension withoutcausing extreme cardio depression. The clinical dosage is 0.25milligrams as bolus injections over two minutes. The second dosage isafter fifteen minutes.
Dihydropyridinesact as relaxers of the smooth muscle without causing depression. Theybring a greater peripheral resistance compared to Diltiazem andverapamil. However, they can depress myocardial contractility, whichcan worsen angina and even lead to death. They can also lead toperipheral oedema.
Thebody eliminates about 70 percent of the administered dose throughfeces and urine within five days of administration (drugs.com, 2016)
DrugAdverse Effects, Contraindications, Precautions, Drug to DrugInteractions, and Drug to Food Interactions, and Drug to HerbInteractions
Patientsshould avoid using alcohol simultaneously with the treatment. Thephysician should monitor liver indices before the commencement oftreatment as patients with liver impairment should take lower doses.Also, patients should avoid taking grapefruit juice as it might leadto increased plasma levels of the drug. Adverse side effects duringuse of verapamil include blue lips and fingernails, sore throat andirregular heartbeat. The verapamil is contraindicated in distinctcircumstances including cases of severe ventricular dysfunction,cardiogenic shock, in case a patient has shown hypersensitivity tothe drug in the past, and Hypotension (G.D. Searle LLC, n.d).
Physiciansmust administer each dose for not less than two minutes whilemonitoring ECG and blood pressure. The dosage relies on theseriousness of the condition and how much an individual can toleratethe drug.
Theinitial dosage for adults is 5 to 10 milligrams IV bolus for not lessthan two minutes. The repeat dosage is 10 milligrams thirty minutesafter the first dose if the patient does not respond adequately(drugs.com, 2016). If the initial treatment responds well, the nexttreatment should be after twelve hours.
Itis crucial to inform patients that verapamil falls under a type ofdrugs called calcium channel blockers. It limits the transmission ofcalcium ions across the myocardial and smooth muscle cells.
Aschenbrenner,D. S., & Venable, S. J. (2013). DrugTherapy in Nursing.Philadelphia: Lippincott Williams & Wilkins
Drugs.com.(2016). Verapamil.Retrieved from < https://www.drugs.com/pro/verapamil.html>
G.D.Searle LLC. (n.d). CALAN- verapamil hydrochloride tablet, film coated.NDA 18-817/S-021
Ellis,M. E., & Ross, H. (2015). ParoxysmalSupraventricular Tachycardia (PSVT).Retrieved from <http://www.healthline.com/health/paroxysmal-supraventricular-tachycardia-psvt#Overview1>