Procainamide (CAS 51-06-9) is a class Ia antiarrhythmic medication used primarily to treat and prevent abnormal heart rhythms. Chemically, it is the amide analogue of the local anesthetic procaine, with significantly different pharmacological properties that make it valuable in cardiology. It is known for its therapeutic efficacy and a distinct side effect profile, particularly its association with drug-induced lupus.
Name :
ProcainamideCAS No. :
51-06-9MF :
C₁₃H₂₁N₃OMW :
235.33Purity :
97%Appearance :
a white to tan crystalline powderStorage Condition :
Solutions should be protected from light.Chemical Properties
Chemical Name: 4-Amino-N-(2-diethylaminoethyl)benzamide
IUPAC Name: 4-Amino-N-[2-(diethylamino)ethyl]benzamide
CAS Registry Number: 51-06-9
Molecular Formula: C₁₃H₂₁N₃O
Molecular Weight: 235.33 g/mol
Chemical Structure: Procainamide consists of a benzene ring substituted with an amino group (para-position) and an amide (–CONH–) linker connected to a diethylaminoethyl side chain. This amide bond, in contrast to the ester bond in procaine, confers greater metabolic stability and is key to its antiarrhythmic action.
Appearance: Typically a white to tan crystalline powder. The pharmaceutical product is commonly available as the hydrochloride salt (Procainamide HCl).
Solubility: Freely soluble in water and soluble in ethanol. The hydrochloride salt is highly water-soluble, which is suitable for intravenous formulation.
Stability: Stable under standard conditions. The amide bond is more resistant to hydrolysis than the ester bond in procaine, but it can degrade under extreme pH, temperature, or light exposure. Solutions should be protected from light.
Melting Point: The hydrochloride salt melts at approximately 165-169 °C.
pKa: Approximately 9.2 (for the alkylamino group), which influences its ionization state and pharmacokinetics.
Biological Activities
Primary Activity: Class Ia Antiarrhythmic Agent. Its main mechanism is the blockade of cardiac voltage-gated sodium channels, particularly in their open/activated state. This action:
1.Decreases conduction velocity in the atria, ventricles, and Purkinje fibers.
2.Prolongs the action potential duration and effective refractory period.
3.Suppresses abnormal automaticity (e.g., in ectopic foci).
Metabolism and Active Metabolite: It is acetylated in the liver by the enzyme N-acetyltransferase 2 (NAT2) to form N-Acetylprocainamide (NAPA), which is also pharmacologically active (a Class III antiarrhythmic, primarily prolonging repolarization). The acetylation rate is genetically determined, leading to "fast" and "slow" acetylator phenotypes, which influences dosing and side effect risk.
Pharmacokinetics: Well-absorbed orally (~75-90%), with a relatively short half-life (2-4 hours for the parent drug; 6-10 hours for NAPA), necessitating frequent dosing or use of sustained-release formulations. It is excreted renally (50-60% unchanged).
Side Effects/Adverse Activities:
Cardiovascular: Hypotension (especially with IV use), QT prolongation, torsades de pointes (a life-threatening arrhythmia).
Immunological: Drug-induced lupus erythematosus (dILE) is a well-known adverse effect, especially in slow acetylators. Symptoms may include arthralgia, myalgia, pleuritis, and rash. Unlike systemic lupus, renal and CNS involvement is rare, and symptoms typically resolve upon drug discontinuation.
Other: Nausea, rash, agranulocytosis (rare but serious).
Biosynthesis
Procainamide is not biosynthesized by living organisms; it is produced by chemical synthesis.
The classic synthetic route involves the condensation of 4-aminobenzoic acid (PABA) with N,N-diethylethylenediamine in the presence of a coupling agent to form the amide bond.
Alternatively, it can be synthesized by modifying procaine, replacing the ester linkage with an amide group, which aligns with its historical discovery as a more stable, cardiologically active analogue.
Applications
FAQs
Q1: What is the main difference between procaine and procainamide?
A1: Procaine is an ester-based local anesthetic with a very short duration due to rapid plasma hydrolysis. Procainamide is an amide-based compound designed to resist hydrolysis. Its primary action is as a Class I antiarrhythmic drug for the heart, not as a local anesthetic. The amide group provides metabolic stability and different target organ effects.
Q2: Why is monitoring important during procainamide therapy?
A2: Close therapeutic drug monitoring (TDM) of both procainamide and its metabolite NAPA is essential to:
Ensure therapeutic levels (procainamide: 4-10 µg/mL; combined procainamide + NAPA: 10-30 µg/mL).
Minimize toxicity risks, especially life-threatening cardiac effects like QT prolongation and torsades de pointes.
Guide dosing in patients with renal impairment, as both parent drug and NAPA are renally excreted.
Q3: What is procainamide-induced lupus, and who is at risk?
A3: It is an autoimmune syndrome caused by the drug, mimicking symptoms of systemic lupus erythematosus (e.g., joint pain, fever, rash, pleurisy). Slow acetylators (individuals with low NAT2 enzyme activity) are at higher risk because they metabolize the drug more slowly, leading to higher exposure and the formation of reactive metabolites that may trigger the autoimmune response. Symptoms usually resolve after stopping the drug.
Q4: Is procainamide still used today?
A4: Yes, but its use has become more selective. It remains an important therapeutic option, particularly for:
Acute treatment of hemodynamically stable ventricular tachycardia.
Management of arrhythmias in specific contexts (e.g., in Wolff-Parkinson-White syndrome).
Due to its side effect profile (especially lupus and proarrhythmia), it is often not a first-line long-term therapy, with drugs like amiodarone or sotalol being preferred in many cases.
Q5: Can I buy procainamide (CAS 51-06-9) for research?
A5: Yes, it is available from reputable chemical and pharmaceutical reference standard suppliers for legitimate research and development purposes. It is sold as a chemical or pharmaceutical standard. Important: Procainamide is a prescription drug strictly regulated for human and veterinary therapeutic use. Research purchases require appropriate institutional documentation and must comply with all applicable regulations, with no intent for unauthorized human or animal administration.
Procaine Hydrochloride CAS 51-05-8 is the water-soluble hydrochloride salt of procaine. It is the specific formulation used in clinical medicine, famously marketed under the brand name Novocain. While its use in mainstream practice has diminished, it remains a historically pivotal drug and is still employed in specific medical and therapeutic contexts.
Details
2-Methyl-3-phenylpropanamide CAS 7499-19-6 is a chiral organic compound primarily recognized as a key synthetic intermediate in pharmaceutical manufacturing. Its structure, featuring a phenylpropionate backbone with a methyl side chain and an amide terminal, makes it a valuable building block, most notably for the synthesis of the Class III antiarrhythmic drug Ibutilide.
Details
Ethyl 3-oxo-4-phenylbutanoate CAS 718-08-1 (also known as ethyl 4-phenyl-3-oxobutanoate or ethyl benzylacetoacetate) is an organic compound belonging to the class of β-keto esters. It features both a ketone and an ester functional group, with a phenyl substituent at the 4-position. Its structure makes it a versatile building block in organic synthesis, particularly in pharmaceutical and fine chemical manufacturing.
Details
2,2-Dimethyl-5-(2-oxo-2-phenylethyl)-1,3-dioxane-4,6-dione CAS 74965-87-0 is a specialized heterocyclic organic compound. Its structure features a 1,3-dioxane-4,6-dione core (a Meldrum's acid derivative) that is substituted at the 2-position with two methyl groups and at the 5-position with a 2-oxo-2-phenylethyl (phenacyl) group. This makes it a versatile, reactive scaffold in synthetic organic chemistry, particularly for constructing more complex molecules.
Details
2-Bromo-1-(3-methylphenyl)propan-1-one CAS 1451-83-8, commonly referred to as 2-bromo-3´-methylpropiophenone or 2-bromo-3-methylpropiophenone, is an α-brominated ketone. It is an aryl alkyl ketone derivative where a bromine atom is substituted at the alpha-carbon of the propiophenone chain, and a methyl group is present on the phenyl ring at the meta position. This structure makes it a valuable alkylating agent and electrophilic building block in organic synthesis.
Details
L-(+)-Tartaric acid CAS 87-69-4 is a naturally occurring organic acid belonging to the class of α-hydroxycarboxylic acids. It is one of the four stereoisomers of tartaric acid, specifically the L-(+) enantiomer, which is the form commonly found in nature. It is a white, crystalline solid widely present in many plants, particularly in grapes, bananas, tamarinds, and citrus fruits. In wine-making, it is a primary acid found in grape must and plays a crucial role in the taste and stability of wine.
Details
Pyrrolidine CAS 123-75-1 is a saturated, five-membered heterocyclic organic compound containing a secondary amine group. It is a cyclic secondary amine and the simplest saturated azacyclopentane, serving as the structural core for numerous alkaloids and pharmaceuticals. The molecule is fully hydrogenated relative to pyrrole, giving it basic properties.
Details
n-Hexane CAS 110-54-3 is a straight-chain, saturated aliphatic hydrocarbon (an alkane) consisting of six carbon atoms. It is a volatile, colorless liquid that is a major component of petroleum ether and gasoline fractions. As a non-polar solvent, it is widely used in industrial applications, but it is also known for its potential neurotoxicity with prolonged exposure.
Details
Contact Us
1st Floor, No. 477, Huancheng West Road, Nanqiao Town, Fengxian District, Shanghai,China
sales@qxscientific.com
+86 -13701740203
IPv6 Network Supported |
Sitemap |
XML |
Blog |
Privacy Policy
Leave A Message
Scan to Wechat/Whatsapp :
English
English
Español
Português
