25,729 articles
Leukonychia totalis
Leukonychia totalis, or porcelain nails, is a rare nail disorder with complete white discoloration of all nails; usually autosomal dominant (PLCD1 gene), neonatal onset, or acquired with cirrhosis, hypoalbuminemia, and other systemic disease.
Leukopenia
Leukopenia (leukocytopenia) is a white blood cell count below 4000/mcL, usually from neutropenia. Causes include chemotherapy, HIV, sepsis, and marrow cancers; Duffy-null (ACKR1/DARC) neutropenia is a benign variant.
Leukoplakia
Oral leukoplakia, also called leukoplakia of the oral mucosa, is a predominantly white oral patch of questionable risk, the most common oral potentially malignant disorder, with about 6.64% pooled malignant transformation risk.
Leukoplakia of vagina
Leukoplakia of vagina (vaginal leukoplakia, ICD-11 GA14.5, ICD-10-CM N89.4) is a white or grey hyperkeratotic plaque of vaginal mucosa caused by HPV, trauma, radiotherapy, or premalignant lesions; a nonspecific finding requiring biopsy.
Leukorrhea
Leukorrhea, also spelled leucorrhoea, is a whitish or yellowish vaginal discharge. It is usually a normal, healthy discharge, but changes in color or odor can signal infection.
Leuprorelin
Leuprorelin is a synthetic GnRH analog that suppresses sex hormones. Approved by the FDA in 1985, it is used to treat prostate cancer, endometriosis, uterine fibroids, and precocious puberty.
Levacetylleucine
Levacetylleucine, also known as N-acetyl-L-leucine and marketed as Aqneursa, is an oral drug approved in 2024 for neurological symptoms of Niemann-Pick disease type C and in 2026 for ataxia in ataxia-telangiectasia.
Levallorphan
Levallorphan (Lorfan) is a discontinued morphinan opioid antagonist with partial kappa-agonist activity, used to reverse opioid respiratory depression; unlike naloxone it depresses respiration and was superseded by it.
Levamfetamine
Levamfetamine (levoamphetamine, L-amphetamine) is the (R)-enantiomer of amphetamine, C9H13N, CAS 156-34-3. Weaker CNS stimulant than dextroamphetamine but stronger peripherally; US anorectic products withdrawn in 1973; distinct from levmetamfetamine.
Levamlodipine
Levamlodipine, also called (S)-amlodipine or levoamlodipine (brand Conjupri), is the active S-enantiomer of the racemic calcium channel blocker amlodipine, FDA-approved December 19, 2019 for hypertension; 5 mg is bioequivalent to 10 mg racemic amlodipine.
Levator ani
Levator ani, the main pelvic diaphragm muscle made of puborectalis, pubococcygeus, and iliococcygeus; supports pelvic viscera, maintains continence, innervated mainly by S3-S4, injured in 13-36% of vaginal deliveries.
Levetiracetam
Levetiracetam (Keppra) is an SV2A-binding antiseizure medication approved by the FDA in 1999 and in the EU in 2000, used as first-line monotherapy or add-on for focal and generalized seizures, with somnolence and headache as common side effects.
Levilimab
Levilimab (BCD-089, Ilsira) is a fully human IgG1 monoclonal antibody against the interleukin-6 receptor from Biocad, Russia; approved there in 2020 for severe COVID-19 cytokine release syndrome and studied in rheumatoid arthritis; ATC L04AC25; no US/EU approval.
Levo-Transposition of the great arteries
Levo-transposition of the great arteries (L-TGA, ccTGA) is a rare congenital heart defect with double discordance leaving the right ventricle systemic; over 80% have associated lesions, and heart block, tricuspid regurgitation, and ventricular failure dominate management.
Levobetaxolol
Levobetaxolol is the active S-isomer of the beta blocker betaxolol, given as eye drops to lower intraocular pressure in open-angle glaucoma and ocular hypertension; it debuted in the early 1980s.
Levobunolol
Levobunolol (levobunolol hydrochloride ophthalmic solution) is a noncardioselective topical beta-blocker, distinct from timolol and betaxolol, used once or twice daily to lower intraocular pressure in open-angle glaucoma and ocular hypertension.
Levocabastine
Levocabastine, a potent selective second-generation H1 antihistamine (C26H29FN2O2), is a topical eye-drop and nasal-spray treatment for allergic conjunctivitis and rhinitis, first approved around 1990 and now discontinued in many markets.
Levocetirizine
Levocetirizine (Xyzal) is the R-enantiomer of cetirizine, an oral second-generation H1 antihistamine for allergic rhinitis and chronic idiopathic urticaria; 5 mg once daily, renally cleared, FDA 2025 warning on severe post-discontinuation itching.
Levodopa
Levodopa (L-DOPA) is a naturally occurring amino acid and direct precursor of dopamine, converted to dopamine in the brain; it has been the gold-standard therapy for Parkinson's motor symptoms since 1967, usually given with carbidopa.
Levodropropizine
Levodropropizine, the levo (S)-enantiomer of dropropizine, is a non-opioid peripheral antitussive acting on airway C-fibers; used for dry cough in Europe (not US-approved), dosed 60 mg three times daily.
Levofloxacin
Levofloxacin (Cravit, Tavanic, Levaquin) is a third-generation fluoroquinolone antibiotic, the S-(-) isomer of ofloxacin, inhibiting DNA gyrase and topoisomerase IV; FDA-approved 1996 for pneumonia, UTIs, skin infections, anthrax, and plague, with a boxed warning for tendon and nerve injury.
Levoketoconazole
Levoketoconazole (Recorlev) is the 2S,4R enantiomer of ketoconazole, an oral cortisol synthesis inhibitor approved by FDA on December 30, 2021 for endogenous hypercortisolemia in adults with Cushing's syndrome, with boxed warnings for hepatotoxicity and QT prolongation.
Levomepromazine
Levomepromazine, also known as methotrimeprazine and sold under names including Nozinan, is a phenothiazine antipsychotic developed by Rhône-Poulenc by the late 1950s, used in psychiatry and palliative care.
Levomethadyl acetate
Levomethadyl acetate (LAAM, levacetylmethadol, ORLAAM), a long-acting full mu-opioid agonist congener of methadone dosed three times weekly for opioid dependence; FDA-approved 1993, withdrawn 2001/2003 over QT prolongation and torsades de pointes.
Levomilnacipran
Levomilnacipran (Fetzima), the L-isomer of milnacipran, is a once-daily SNRI antidepressant approved by the FDA in July 2013 for major depressive disorder; NNT 9 for response, notable blood pressure and heart rate increases.
Levonadifloxacin
Levonadifloxacin (WCK 771, EMROK), a benzoquinolizine fluoroquinolone and arginine salt of S(–)-nadifloxacin, is an anti-MRSA antibiotic approved in India in 2019, with the oral L-alanine prodrug alalevonadifloxacin (WCK 2349, EMROK O).
Levonordefrin
Levonordefrin (nordefrin, Cobefrin, Corbadrine) is a levo-isomer sympathomimetic vasoconstrictor used in dental anesthesia, available in North America only as 2% mepivacaine with 1:20,000 levonordefrin; about one-sixth epinephrine's potency, contraindicated with tricyclic antidepressants.
Levonorgestrel
Levonorgestrel (LNG), also known as Plan B One-Step, is a second-generation progestin used in emergency contraceptive pills (1.5 mg), LNG intrauterine systems, and former implants; it prevents pregnancy by delaying ovulation.
Levopropoxyphene
Levopropoxyphene (L-propoxyphene), the (2R,3S) enantiomer of propoxyphene, is a discontinued centrally acting antitussive first approved in 1962; unlike its analgesic mirror image dextropropoxyphene, it suppresses cough without opioid pain relief.
Levornidazole phosphate disodium for injection
Levornidazole phosphate disodium for injection (注射用磷酸左奥硝唑酯二钠, brand Xinrui) is a Chinese Class 1 nitroimidazole antibiotic, a phosphate prodrug of levornidazole (S-ornidazole), approved 26 May 2021 for Yangtze River Pharmaceutical for anaerobic and amebic infections.