25,729 articles
Oxymatrine
Oxymatrine (matrine N-oxide, Ammothamnine), a quinolizidine alkaloid from Sophora flavescens roots, studied for anticancer, antiviral, anti-inflammatory, and antifibrotic effects; not approved as an EU pesticide active substance.
Oxymetazoline
Oxymetazoline (Afrin, Rhofade) is an imidazoline alpha-adrenergic agonist vasoconstrictor used as a 0.05% OTC nasal decongestant spray and as 1% cream for rosacea erythema; overuse risks rebound congestion.
Oxymetholone
Oxymetholone (Anadrol-50) is a 17α-alkylated anabolic-androgenic steroid, a synthetic testosterone derivative once FDA-approved for anemias from deficient red cell production; now discontinued in the US, hepatotoxic, and listed as reasonably anticipated to be a human carcinogen.
Oxymorphone
Oxymorphone (14-hydroxydihydromorphinone), brand Opana/Opana ER, is a semisynthetic Schedule II mu-opioid agonist painkiller; injectable form approved 1959, oral IR/ER 2006, reformulated ER withdrawn 2017 after abuse shifted to injection.
Oxypertine
Oxypertine (WIN 18,501-2, Integrin) is a phenylpiperazine antipsychotic introduced in the 1960s for schizophrenia; a dopamine antagonist and monoamine depleter, now used predominantly in Japan.
Oxyphenbutazone anhydrous
Oxyphenbutazone anhydrous (UNII A7D84513GV, CAS 129-20-4, Tanderil/Tandearil) is the water-free active form of oxyphenbutazone, a pyrazolidinedione NSAID and active metabolite of phenylbutazone, withdrawn worldwide by 1985 for fatal bone marrow toxicity.
Oxyphencyclimine
Oxyphencyclimine (Daricon) is a synthetic tertiary amine antimuscarinic anticholinergic drug, ATC A03AA01, C20H28N2O3, introduced 1958, used for peptic ulcer and gastrointestinal smooth muscle spasm, reducing gastric acid secretion.
Oxyphenonium
Oxyphenonium (Antrenyl, oxyphenonium bromide) is a synthetic quaternary ammonium anticholinergic, first US-approved 1952, used for visceral spasms and peptic ulcer adjunct therapy; dual antimuscarinic and musculotropic action, targets CHRM3/CHRM1, now discontinued in the US.
Oxytetracycline
Oxytetracycline (Terramycin) is a broad-spectrum tetracycline antibiotic isolated from Streptomyces rimosus by Pfizer in 1950; a WHO essential medicine (WATCH) for trachoma and eye infections, also used in veterinary medicine and agriculture.
Oxytocin
Oxytocin, a cyclic nonapeptide hormone of the posterior pituitary, drives labor contractions and milk ejection; first synthesized by Vincent du Vigneaud (1953, Nobel 1955), it is a standard obstetric drug and a debated social-behavior research target.
Oxytocin deficiency
Oxytocin deficiency is a clinically recognized state of reduced or impaired oxytocin signaling, classified in ICD-11 as isolated or combined with other pituitary deficiencies, with no validated routine test.
Ozagrel
Ozagrel (ozagrel sodium; brands Xanbon, Katalclot) is a thromboxane A2 synthase inhibitor antiplatelet drug approved in Japan for post-SAH vasospasm and acute cerebral thrombosis, used for ischemic stroke in Japan, China, and Korea.
Ozaki procedure
The Ozaki procedure, also called aortic valve neocuspidization (AvNeo), is a cardiac operation that rebuilds the aortic valve from the patient's own pericardium, developed by Shigeyuki Ozaki in 2007.
Ozanimod
Ozanimod (Zeposia, RPC1063) is an oral S1P1/S1P5 receptor modulator approved in 2020 for relapsing multiple sclerosis and 2021 for ulcerative colitis, dosed 0.92 mg daily after titration.
Ozenoxacin
Ozenoxacin (Xepi, Ozanex) is a nonfluorinated quinolone topical antibiotic, 1% cream, FDA approved December 2017 for impetigo due to S. aureus or S. pyogenes in patients 2 months and older, applied twice daily for 5 days.
Ozone therapy
Ozone therapy (oxy-ozone therapy, ozonotherapy): administration of 0.5–5% oxygen-ozone mixtures via autohemotherapy, insufflation, or topical routes; mechanistically plausible but low-certainty evidence, FDA states no established medical role.
P wave (electrocardiography)
P wave (electrocardiography): first positive ECG deflection, representing atrial depolarization; named P by Einthoven. Normal duration under 120 ms, amplitude under 2.5 mm in limb leads, axis 0 to +75 degrees.
P3 trial (NCT02675114)
PARTNER 3 (P3 trial, NCT02675114): randomized trial of transfemoral SAPIEN 3 TAVR vs surgical valve replacement in 1,000 low-risk severe aortic stenosis patients; TAVR superior at 1 year, similar outcomes through 7 years.
P3HR-1
P3HR-1 (P3HR1) is a human B-cell line derived from a Burkitt lymphoma and infected with Epstein-Barr virus, used as a standard laboratory producer of the virus.
PA001 trial
PA001 (NCT05587088) is a phase Ib/II trial at Hospital Universitario San Ignacio, Bogotá, testing the Petiveria alliacea (Anamu) extract Esperanza with chemotherapy in metastatic gastrointestinal tumors and acute leukemias.
Pabinafusp alfa
Pabinafusp alfa (JR-141, IZCARGO) is a blood-brain barrier-penetrating enzyme replacement therapy, human iduronate-2-sulfatase fused to an anti-transferrin receptor antibody, approved in Japan in 2021 for MPS II (Hunter syndrome).
Pac-14028
PAC-14028 (asivatrep) is Amorepacific's topical, nonsteroidal, selective TRPV1 antagonist (IC50 6.2 nM) for atopic dermatitis; positive phase 2b and CAPTAIN-AD phase 3 trials in Korea, cosmetic AESTURA use, not US-approved.
PACE study (NCT04615104)
PACE (NCT04615104), Pelvic and Acetabular Fracture: A Prospective Observational Study, is a Wake Forest-sponsored prospective cohort following about 200 adults after pelvic ring or acetabular fractures, operative or nonoperative, measuring return to work, PROMIS-29, healing, and mobility over 24 months.
Paced Auditory Serial Addition Test
The Paced Auditory Serial Addition Test (PASAT) is a neuropsychological test in which digits heard at a fixed pace are added in pairs, used in brain injury and multiple sclerosis.
Pacemaker failure
Pacemaker failure is the malfunction of an implanted cardiac pacemaker, its leads, or its programming so that it fails to keep an adequate heart rate.
Pacemaker implantation
Pacemaker implantation, also called permanent pacemaker implantation, is a surgical procedure placing a pulse generator and leads under the skin to treat slow heart rhythms, with nearly one million implants yearly.
Pacemaker neuron
A pacemaker neuron is a neuron that generates rhythmic bursts of action potentials independently of synaptic input, driving circadian rhythms in the suprachiasmatic nucleus and respiration in the preBötzinger complex.
Pacemaker syndrome
Pacemaker syndrome: iatrogenic symptoms from ventricular pacing causing AV dyssynchrony, first described 1969; incidence 2-80%; treated by reprogramming or dual-chamber upgrade.
Pachydermoperiostosis
Pachydermoperiostosis, or primary hypertrophic osteoarthropathy (Touraine-Solente-Gole syndrome), is a rare hereditary disorder with digital clubbing, pachydermia, and periostosis, caused by HPGD or SLCO2A1 mutations elevating prostaglandin E2.
Pachymeningitis
Pachymeningitis, also called hypertrophic pachymeningitis in its fibrotic form, is inflammation and thickening of the dura mater (ICD-11 8E41) caused by infection, autoimmune disease including ANCA and IgG4-related disease, or cancer, diagnosed by MRI and dural biopsy.