lhydralazine

Lhydralazine, or L-hydralazine, is described in some sources as the levorotatory enantiomer of the vasodilator hydralazine. There is little publicly available information identifying L-hydralazine as a distinct, marketed pharmaceutical entity. Most clinical and pharmacological literature discusses hydralazine as a racemate or as the active component in standard formulations; no widely marketed product is identified specifically as L-hydralazine.

Pharmacology and mechanism are largely described for hydralazine in general. Hydralazine is a direct-acting vasodilator that primarily relaxes arteriolar smooth muscle; the exact molecular mechanism is not fully understood and may involve multiple pathways, including effects on nitric oxide signaling and potassium channels. It is not well established whether the levo-enantiomer has different potency, efficacy, or safety compared with the racemate, as enantiomer-specific data are sparse in accessible sources.

Pharmacokinetics of hydralazine involve hepatic metabolism by N-acetylation, with significant interindividual variation due to acetylator status (fast vs slow). Enantiomer-specific pharmacokinetics for L-hydralazine are not well documented in the public record, and there is no clear consensus on how the levo-enantiomer behaves relative to the racemate.

Clinical use and safety: there is no widely recognized clinical indication for L-hydralazine as a separate enantiomer. In practice, hydralazine is used in its racemic form, for indications such as hypertension and, in some cases, heart failure, often with additional agents to offset reflex tachycardia and fluid retention. Adverse effects associated with hydralazine—tachycardia, edema, headaches, and potential drug-induced lupus—are relevant considerations if an enantiomer were used clinically, but enantiomer-specific risk data are not well established.

See also: Hydralazine, vasodilators, drug-induced lupus erythematosus.