Wikipedia:WikiProject Chemicals/Chembox validation/VerifiedDataSandbox and Prajmaline: Difference between pages

{{short description|Chemical compound}}

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| CAS_number = 35080-11-6

'''Prajmaline''' (Neo-gilurythmal)<ref name="Jan">{{cite journal |vauthors=Janicki K, Orski J, Kakol J |title=[Antiarrhythmic effects of prajmaline (Neo-Gilurythmal) in stable angina pectoris in light of Holter electrocardiographic monitoring] |language=Polish |journal=Przegląd Lekarski |volume=52 |issue=10 |pages=485–491 |year=1995 |pmid=8834838}}</ref> is a class Ia [[antiarrhythmic agent]]<ref name="Weir">{{cite journal |vauthors=Weirich J, Antoni H |title=Differential analysis of the frequency-dependent effects of class 1 antiarrhythmic drugs according to periodical ligand binding: implications for antiarrhythmic and proarrhythmic efficacy |journal=Journal of Cardiovascular Pharmacology |volume=15 |issue=6 |pages=998–1009 | date=June 1990 |pmid=1694924 |doi=10.1097/00005344-199006000-00019|doi-access=free }}</ref> which has been available since the 1970s.<ref name="Kopp">{{cite journal |vauthors=Köppel C, Oberdisse U, Heinemeyer G |title=Clinical course and outcome in class IC antiarrhythmic overdose |journal=Clinical Toxicology |volume=28 |issue=4 |pages=433–44 |year=1990 |pmid=2176700 |doi=10.3109/15563659009038586}}</ref> Class Ia drugs increase the time one action potential lasts in the heart.<ref>{{cite journal |vauthors=Milne JR, Hellestrand KJ, Bexton RS, Burnett PJ, Debbas NM, Camm AJ |title=Class 1 antiarrhythmic drugs--characteristic electrocardiographic differences when assessed by atrial and ventricular pacing |journal=European Heart Journal |volume=5 |issue=2 |pages=99–107 | date=February 1984 |pmid=6723689 |doi=10.1093/oxfordjournals.eurheartj.a061633}}</ref> Prajmaline is a semi-synthetic propyl derivative of [[ajmaline]], with a higher bioavailability than its predecessor.<ref>{{cite journal |vauthors=Hinse C, Stöckigt J |title=The structure of the ring-opened N beta-propyl-ajmaline (Neo-Gilurytmal) at physiological pH is obviously responsible for its better absorption and bioavailability when compared with ajmaline (Gilurytmal) |journal=Die Pharmazie |volume=55 |issue=7 |pages=531–2 | date=July 2000 |pmid=10944783}}</ref> It acts to stop [[arrhythmias]] of the heart through a frequency-dependent block of cardiac sodium channels.<ref name="Weir"/>

==Mechanism==

Prajmaline causes a resting block in the heart.<ref name="Lang">{{cite journal |vauthors=Langenfeld H, Weirich J, Köhler C, Kochsiek K |title=Comparative analysis of the action of class I antiarrhythmic drugs (lidocaine, quinidine, and prajmaline) in rabbit atrial and ventricular myocardium |journal=Journal of Cardiovascular Pharmacology |volume=15 |issue=2 |pages=338–45 | date=February 1990 |pmid=1689432 |doi=10.1097/00005344-199002000-00023|doi-access=free }}</ref> A resting block is the depression of a person's Vmax after a resting period. This effect is seen more in the atrium than the ventricle.<ref name="Lang"/> The effects of some Class I antiarrhythmics are only seen in a patient who has a normal heart rate (~1&nbsp;Hz).<ref name="Langen">{{cite journal |vauthors=Langenfeld H, Köhler C, Weirich J, Kirstein M, Kochsiek K |title=Reverse use dependence of antiarrhythmic class Ia, Ib, and Ic: effects of drugs on the action potential duration? |journal=Pacing and Clinical Electrophysiology |volume=15 |issue=11 Pt 2 |pages=2097–102 | date=November 1992 |pmid=1279606 |doi=10.1111/j.1540-8159.1992.tb03028.x|s2cid=25864256 }}</ref> This is due to the effect of a phenomenon called reverse use dependence.<ref name="Langen"/> The higher the heart rate, the less effect Prajmaline will have.

==Uses==

The drug Prajmaline has been used to treat a number of cardiac disorders. These include: coronary artery disease,<ref name="Sow">{{cite journal |vauthors=Sowton E, Sullivan ID, Crick JC |title=Acute haemodynamic effects of ajmaline and prajmaline in patients with coronary heart disease |journal=European Journal of Clinical Pharmacology |volume=26 |issue=2 |pages=147–50 |year=1984 |pmid=6723753 |doi=10.1007/bf00630278|s2cid=20512025 }}</ref><ref name="Hand">{{cite journal |vauthors=Handler CE, Kritikos A, Sullivan ID, Charalambakis A, Sowton E |title=Effects of oral prajmaline bitartrate on exercise test responses in patients with coronary artery disease |journal=European Journal of Clinical Pharmacology |volume=28 |issue=4 |pages=371–4 |year=1985 |pmid=4029242 |doi=10.1007/bf00544352|s2cid=521671 }}</ref> angina,<ref name="Sow"/><ref name="Hand"/> [[paroxysmal tachycardia]] and Wolff–Parkinson–White syndrome.<ref name="Jan"/> Prajmaline has been indicated in the treatment of certain disorders where other antiarrhythmic drugs were not effective.<ref name="Jan"/>

==Administration==

Prajmaline can be administered orally,<ref name="Hand"/> parenterally<ref name="Sow"/> or intravenously.<ref name="Sow"/> Three days after the last dose, a limited effect has been observed. Therefore, it has been suggested that treatment of arrhythmias with Prajmaline must be continuous to see acceptable results.<ref name="Jan"/>

==Pharmacokinetics==

The main metabolites of Prajmaline are: 21-carboxyprajmaline and hydroxyprajmaline. Twenty percent of the drug is excreted in the urine unchanged.

Daily therapeutic dose is 40–80&nbsp;mg.

Distribution half-life is 10 minutes.

Plasma protein binding is 60%.

Oral bioavailability is 80%.

Elimination half-life is 6 hours.

Volume of distribution is 4-5 L/kg.

<ref name="Kopp"/>

==Side Effects==

There are no significant adverse side-effects of Prajmaline when taken alone and with a proper dosage.<ref name="Jan"/><ref name="Sow"/><ref name="Hand"/> Patients who are taking other treatments for their symptoms (e.g. beta blockers and nifedipine) have developed minor transient conduction defects when given Prajmaline.<ref name="Sow"/>

==Overdose==

An overdose of Prajmaline is possible. The range of symptoms seen during a Prajmaline overdose include: no symptoms, nausea/vomiting, [[bradycardia]], tachycardia, hypotension, and death.<ref name="Kopp"/>

==Other Potential Uses==

Due to Prajmaline's sodium channel-blocking properties, it has been shown to protect rat white matter from anoxia (82 +/- 15%).<ref name="Stys">{{cite journal |author=Stys PK |title=Protective effects of antiarrhythmic agents against anoxic injury in CNS white matter |journal=Journal of Cerebral Blood Flow and Metabolism |volume=15 |issue=3 |pages=425–32 | date=May 1995 |pmid=7714000 |doi=10.1038/jcbfm.1995.53|doi-access=free }}</ref><ref name="Malek">{{cite journal |vauthors=Malek SA, Adorante JS, Stys PK |title=Differential effects of Na-K-ATPase pump inhibition, chemical anoxia, and glycolytic blockade on membrane potential of rat optic nerve |journal=Brain Research |volume=1037 |issue=1–2 |pages=171–9 | date=March 2005 |pmid=15777766 |doi=10.1016/j.brainres.2005.01.003|s2cid=29226181 }}</ref> The concentration used causes little suppression of the preanoxic response.<ref name="Stys"/><ref name="Malek"/>

==References==

{{Reflist}}

{{Antiarrhythmic agents}}

[[Category:Alkaloids]]

[[Category:Sodium channel blockers]]

[[Category:Secondary alcohols]]