Characteristics of substance Naproxen Sodium
NSAIDs. Naproxen – white or almost white crystalline powder, odorless. Soluble in lipids, is practically insoluble in water at low pH, freely soluble in water at high pH. Octanol / water at pH 7,4 is 1.6-1.8. The molecular weight of 230.26.
Naproxen sodium – a white crystalline solid or white-cream color, freely soluble in water at neutral pH. The molecular weight of 252.24.
Pharmacology Naproxen Sodium
Pharmacological action – anti-inflammatory, analgesic, antipyretic, antiaggregatory. Reduces the activity of cyclooxygenase (COX-1 and COX-2), resulting in a disturbed synthesis of PG. After oral administration of naproxen and naproxen sodium is rapidly and completely absorbed from the gastrointestinal tract, bioavailability – 95%. Cmax levels achieved within 2-4 hours after taking naproxen and 1-2 h after administration of naproxen sodium. Protein binding – 98-99%. Naproxen concentration in plasma increases in proportion to dose, exceeding a single dose of 500 mg of proportionality is violated. T1 / 2 of plasma – 12-17 hours Biotransformiruetsya 6-O-dezmetilnaproksen. Volume of distribution of naproxen – 0.16 L / kg, clearance – 0.13 ml / min / kg. The equilibrium concentration of naproxen is achieved after 4-5 days of continuous use. Approximately 95% excreted in urine, 1% – diarrhea, dyspepsia, stomatitis, 1% – vertigo.
Cardio-vascular system and blood (hematopoiesis, hemostasis):> 1% – heartbeat The respiratory system: 3-9% – dyspnea.
For the skin: 3-9% – ecchymosis.
Genitourinary: 1% – increased sweating, purpura, thirst.
Side effects encountered with a frequency From the digestive tract: colitis, gematemezis, jaundice, pancreatitis, melena.
Genitourinary: nephritis glomerular, hematuria, hyperkalemia, interstitial nephritis, nephrotic syndrome, renal failure, renal papillary necrosis.
Cardio-vascular system and blood (blood, hemostasis): agranulocytosis, eosinophilia, granulocytopenia, leukopenia, and thrombocytopenia.
The nervous system and sensory organs: depression, abnormal dreams, inability to concentrate, insomnia, malaise, myalgia, muscular weakness.
Side effects encountered with a frequency Cardio-vascular system and blood (blood, hemostasis): aplastic anemia, hemolytic anemia.
Since the nervous system and sensory organs: aseptic meningitis, cognitive dysfunction.
From the digestive tract: gastrointestinal ulceration nepepticheskoe, ulcerative stomatitis.
Allergic reaction: epidermal necrolysis, erythema multiforme, Stevens-Johnson syndrome, urticaria, photosensitivity reactions, such as epidermolysis bullosa porfiricheskomu.
Other: vasculitis, giper-/gipoglikemiya, alopecia, photodermatitis.
Interaction Naproxen Sodium
Increases toxicity of hydantoin, indirect anticoagulants, sulfonamides, methotrexate (blocks tubular secretion). Reduces the natriuretic and diuretic effect of furosemide, hypotension caused by beta-blockers. Reduces the excretion of lithium salts, and increases its concentration in plasma. Antacids containing magnesium and aluminum, and sucralfate may decrease the absorption of naproxen.
Overdose Naproxen Sodium
Symptoms: drowsiness, lethargy, dizziness, epigastric pain, abdominal discomfort, heartburn, indigestion, nausea, transient hepatic dysfunction, gipoprotrombinemii, renal dysfunction, metabolic acidosis, apnea, disorientation, vomiting, possibly bleeding from the gastrointestinal tract is rare – hypertension, acute renal failure, respiratory depression, coma.
Treatment: gastric lavage, induction of vomiting and / or introduction of activated charcoal (60-100 g – For adults, 1-2 g / kg – for children) and / or appointment of osmotic laxatives, symptomatic and supportive therapy. The specific antidote is not found. Forced diuresis, alkalization of urine or dialysis are not effective because of its high protein binding.
Dosage and administration Naproxen Sodium
Inside, the average adult dose – 250-500 mg 2 times a day, maximum single dose – 500 mg, the maximum daily – 1750 mg in two divided doses (morning and night).
Average daily intake for children from 1 year to 5 years – 2.5-10 mg / kg body weight of 1-3 reception, children over 5 years – 10 mg / kg per day in 2 divided doses, the usual duration of treatment – 2 weeks ( preferred dosage form for children is a suspension) in juvenile arthritis in children older than 5 years of daily dose is 10 mg / kg.
Precautions Naproxen Sodium
With prolonged use should be monitored for liver function and kidney of the peripheral blood.
If necessary, determine the 17-ketosteroids or 5 oxyindoleacetic acid treatment should be stopped 48 hours before the study.
