Vidarabine is rapidly deaminated, possibly within the cornea, by adenosine deaminase to ara-hypoxanthine. Ara-hypoxanthine also possesses antiviral activity but substantially less than that of vidarabine.
Although an interaction has not been clearly established, concurrent administration of vidarabine and allopurinol has been associated with tremors, anemia, nausea, pain, and pruritus in some patients. Animal and in vitro studies suggest that allopurinol may interfere with the metabolism of vidarabine.
Acyclovir and vidarabine both exhibit anti-herpetic activity. Because different mechanisms of action of vidarabine and acyclovir have been reported, /the authors/ analyzed their combined anti-herpetic activity on plaque formation of herpes simplex virus (HSV)-1, HSV-2, and varicella-zoster virus (VZV) by isobolograms. The results indicate that acyclovir and vidarabine have a synergistic effect on wild type HSV-1, HSV-2, and VZV. ...
/SIGNS AND SYMPTOMS/ Iv vidarabine causes dose-related GI toxicity, acute neurotoxicities, painful peripheral neuropathy, weakness, hypokalemia, rash, elevated transaminases, anemia, and leukopenia or thrombocytopenia.
/SIGNS AND SYMPTOMS/ Like other ophthalmic ointments, vidarabine may produce a temporary visual haze. Burning, itching, and mild irritation of the affected eye are the most common adverse effects of topical vidarabine therapy; however, lacrimation, foreign body sensation, conjunctival injection, superficial punctate keratitis, pain, photophobia, punctal occlusion, and sensitivity may also occur. Uveitis, stromal edema, secondary glaucoma, trophic defects, corneal vascularization, and hyphema have also been reported, but appear to be disease related.
来源:Hazardous Substances Data Bank (HSDB)
吸收、分配和排泄
吸收
系统性地吸收阿昔洛韦在眼部给药和吞咽泪液后不应被预期发生。
Systemetic absorption of vidarabine should not be expected to occur following ocular administration and swallowing lacrimal secretions.
Vira-A is rapidly deaminated to arabinosylhypoxanthine (Ara-Hx), the principal metabolite. ...Because of the low solubility of Vira-A, trace amounts of both Vira-A and Ara-Hx can be detected in the aqueous humor only if there is an epithelial defect in the cornea. If the cornea is normal, only trace amounts of Ara-Hx can be recovered from the aqueous humor. Systemic absorption of Vira-A should not be expected to occur following ocular administration and swallowing lacrimal secretions.
Vidarabine is poorly absorbed following oral, im, or SC administration. Following iv administration of vidarabine, 75-87% of the dose is rapidly deaminated by adenosine deaminase to ara-hypoxanthine. Ara-hypoxanthine also possesses antiviral activity but substantially less than that of vidarabine. Following slow iv administration of vidarabine 10 mg/kg in adults, peak plasma concentrations of the drug range from 0.2-0.4 ug/mL and peak plasma concentrations of ara-hypoxanthine range from 3-6 ug/mL. Plasma concentrations of vidarabine and ara-hypoxanthine are higher and more prolonged in patients with renal impairment.
Vidarabine and ara-hypoxanthine are widely distributed into body tissues and fluids and readily cross the blood-brain barrier. In patients with normal meninges, ara-hypoxanthine concentrations in the CSF are about 33-35% of concurrent plasma concentrations. Vidarabine crosses the placenta in animals. It is not known if vidarabine is distributed into milk. ... Vidarabine is 20-30% bound and ara-hypoxanthine is 0-3% bound to plasma proteins.
Vidarabine and ara-hypoxanthine are excreted mainly by the kidneys. Within 24 hours following iv administration of vidarabine 15 mg/kg in patients with normal renal function, 1-3% of the dose is excreted in urine as vidarabine and 41-53% of the dose is excreted as ara-hypoxanthine. There is no evidence of fecal excretion of the drug or metabolite.
The present invention relates compounds of the formula: or pharmaceutically acceptable salts thereof, useful as sodium channel blockers, as well as compositions containing the same, processes for the preparation of the same, and therapeutic methods of use therefore in promoting hydration of mucosal surfaces and the treatment of diseases including cystic fibrosis, chronic obstructive pulmonary disease, asthma, bronchiectasis, acute and chronic bronchitis, emphysema, and pneumonia.
CHLORO-PYRAZINE CARBOXAMIDE DERIVATIVES WITH EPITHELIAL SODIUM CHANNEL BLOCKING ACTIVITY
申请人:Parion Sciences, Inc.
公开号:US20140171447A1
公开(公告)日:2014-06-19
This invention provides compounds of the formula I:
and their pharmaceutically acceptable salts, useful as sodium channel blockers, compositions containing the same, therapeutic methods and uses for the same and processes for preparing the same.
The present invention is directed to novel compounds of Formula (I) and pharmaceutically acceptable salts thereof,
pharmaceutical compositions and their use as dual chromaphores having inhibitory activity against PDE4 and muscarinic acetylcholine receptors (mAChRs), and thus being useful for treating respiratory diseases.
[EN] DUAL PHARMACOPHORES - PDE4-MUSCARINIC ANTAGONISTICS<br/>[FR] PHARMACOPHORES DUALS, ANTAGONISTES DES RÉCEPTEURS MUSCARINIQUES ET INHIBITEURS DE L'ACTIVITÉ PDE4
申请人:GLAXO GROUP LTD
公开号:WO2009100169A1
公开(公告)日:2009-08-13
The present invention is directed to novel compounds of Formula's (I) - (VI), and pharmaceutically acceptable salts thereof, pharmaceutical compositions and their use in therapy, for example as inhibitors of phosphodiesterase type IV (PDE4) and as antagonists of muscarinic acetylcholine receptors (mAChRs), in the treatment of and/or prophylaxis of respiratory diseases, including inflammatory and/or allergic diseases such as chronic obstructive pulmonary disease (COPD), asthma, rhinitis (e.g. allergic rhinitis), atopic dermatitis or psoriasis.
[EN] AMINOQUINAZOLINE COMPOUNDS AS A2A ANTAGONIST<br/>[FR] COMPOSÉS D'AMINOQUINAZOLINE COMME ANTAGONISTES D'A2A
申请人:MERCK SHARP & DOHME
公开号:WO2016126570A1
公开(公告)日:2016-08-11
The present invention is directed to compounds of generic formula I: or pharmaceutically acceptable salts thereof that are believed to be useful as an A2A-receptor antagonist.