Tet 36.6® rapid with acacia flavor

INSTRUCTIONS FOR MEDICAL USE OF THE MEDICINAL PRODUCT Tet 36.6® RAPID with acacia flavour (Tet 36.6® RAPID with acacia flavour)

Composition:

Active substances: paracetamol, phenylephrine hydrochloride, pheniramine maleate, ascorbic acid;

1 sachet contains: paracetamol 650 mg, phenylephrine hydrochloride 10 mg, pheniramine maleate 20 mg, ascorbic acid 50 mg;

Excipients: sodium citrate, citric acid, acacia flavouring, colloidal anhydrous silicon dioxide, white sugar, sucrose.

Pharmaceutical form. Oral powder for solution.

Main physicochemical properties: granular, free-flowing powder consisting of a mixture of white and pale-yellow granules with an acacia odour.

Pharmacotherapeutic group.
Analgesics and antipyretics. Paracetamol combinations without psychotropic agents. ATC code N02BE51.

Pharmacological properties.

Pharmacodynamics.

Paracetamol exerts antipyretic, analgesic, and weak anti-inflammatory effects. It inhibits prostaglandin synthesis in the central nervous system (CNS) and blocks transmission of pain impulses.

Pheniramine maleate is a histamine H1-receptor blocker that reduces vascular permeability and relieves lacrimation, as well as itching of eyes and nose.

Phenylephrine hydrochloride is an α-adrenergic agonist that produces vasoconstrictive action, reducing swelling of the nasal mucosa and paranasal sinuses.

Ascorbic acid enhances nonspecific resistance of the body.

Pharmacokinetics.

Paracetamol is well absorbed, penetrates the placental barrier, and passes to a small extent into breast milk. It is metabolized by the cytochrome P450 system, excreted by the kidneys, with a half-life of 1–4 hours. Duration of action is 3–4 hours.

Pheniramine maleate is well absorbed from the gastrointestinal tract. It is metabolized in the liver by the cytochrome P450 system, with a half-life of 16–18 hours; 70–83% is excreted by the kidneys.

The effect of phenylephrine hydrochloride begins rapidly and lasts approximately 20 minutes. It is metabolized in the liver or gastrointestinal tract and excreted by the kidneys.

Ascorbic acid is rapidly absorbed from the gastrointestinal tract, metabolized in the liver, and excreted by the kidneys.

Clinical characteristics.

Indications.

Symptomatic treatment of acute respiratory infections and influenza:

• elevated body temperature,
• headache,
• nasal congestion,
• rhinorrhea,
• muscle pain and aching.

Contraindications.

Hypersensitivity to the components of the drug; severe impairment of liver and/or kidney function; congenital hyperbilirubinemia; glucose-6-phosphate dehydrogenase deficiency; phenylketonuria; alcoholism; blood disorders; leukopenia; anemia; severe forms of arrhythmia, arterial hypertension, atherosclerosis, ischemic heart disease; hyperthyroidism; acute pancreatitis; prostate hypertrophy with urinary retention; bladder neck obstruction; pyloroduodenal obstruction; bronchial asthma; closed-angle glaucoma; pheochromocytoma; thrombosis; thrombophlebitis; diabetes mellitus; epilepsy; states of increased excitation; sleep disorders associated with treatment with tricyclic antidepressants, β-blockers, other sympathomimetics, appetite-suppressing or appetite-stimulating agents, and amphetamine-like psychostimulants; concomitant therapy and within 2 weeks after the use of MAO inhibitors.

Interaction with other medicinal products and other forms of interaction.

The absorption rate of paracetamol may be increased when used with metoclopramide and domperidone, and decreased with cholestyramine (this effect is negligible if cholestyramine is administered 1 hour apart). With prolonged use of paracetamol, the anticoagulant effect of warfarin and other coumarin derivatives may be enhanced, increasing the risk of bleeding. This effect is not pronounced with occasional use of paracetamol. Barbiturates reduce the antipyretic effect of paracetamol. Hepatotoxic drugs increase the likelihood of paracetamol accumulation and overdose. The risk of paracetamol hepatotoxicity increases when taking drugs that induce hepatic microsomal enzymes (barbiturates; anticonvulsants – phenytoin, phenobarbital, carbamazepine; and antituberculosis agents – rifampicin, isoniazid). Paracetamol: reduces the efficacy of diuretics; may prolong the half-life of chloramphenicol; may induce lamotrigine metabolism in the liver, thereby reducing its bioavailability and efficacy. Regular concomitant use of paracetamol and zidovudine may result in neutropenia and increased risk of liver damage. When probenecid is taken, the dose of paracetamol should be reduced, as probenecid affects paracetamol metabolism. Paracetamol may interfere with the determination of uric acid levels by the phosphotungstic acid method. Hepatotoxicity of paracetamol may be enhanced by prolonged or excessive alcohol consumption. Do not use concurrently with alcohol.

Paracetamol should be used with caution when administered concomitantly with flucloxacillin, as co-administration has been associated with metabolic acidosis with a high anion gap as a result of pyroglutamic acidosis, particularly in patients with risk factors (see section "Special precautions").

Phenylephrine interaction with MAO inhibitors results in a hypertensive effect; with tricyclic antidepressants (amitriptyline) – increases the risk of cardiovascular adverse reactions; with digoxin and cardiac glycosides – may lead to arrhythmias and infarction; with other sympathomimetics – increases the risk of adverse cardiovascular reactions and arterial hypertension; may reduce the effectiveness of β-blockers and other antihypertensive agents (reserpine, methyldopa, debrisoquin, guanethidine), increasing the risk of arterial hypertension and adverse cardiovascular reactions. Concomitant use of phenylephrine with ergot alkaloids (ergotamine and methysergide) may increase the risk of ergotism.

Ascorbic acid, when taken orally, enhances iron absorption; increases blood levels of ethinylestradiol, penicillins, and tetracyclines; reduces blood levels of antipsychotic drugs and phenothiazine derivatives; reduces the effectiveness of heparin and indirect anticoagulants; increases the risk of crystalluria during salicylate therapy and the risk of glaucoma during glucocorticoid therapy; high doses reduce the effectiveness of tricyclic antidepressants. Ascorbic acid should be taken only 2 hours after deferoxamine injection, as their concomitant use increases iron toxicity, especially in the myocardium, potentially leading to cardiac decompensation. Prolonged use of high doses during disulfiram treatment inhibits the disulfiram-alcohol reaction. Absorption of ascorbic acid is reduced when taking oral contraceptives, consuming fruit or vegetable juices, or alkaline beverages.

Pheniramine enhances the anticholinergic effects of atropine, spasmolytics, tricyclic antidepressants, and antiparkinsonian agents; it inhibits the action of anticoagulants. Concomitant use of pheniramine with sedatives, barbiturates, tranquilizers, neuroleptics, anesthetics, narcotic analgesics, and alcohol may significantly enhance its depressant effects.

Special precautions for use.

Do not exceed the recommended doses. If symptoms do not improve within 5 days or are accompanied by high fever, chills lasting more than 3 days, rash, or persistent headache, consult a physician, as these manifestations may indicate a more serious condition.

Due to the risk of severe liver damage in overdose, do not use concomitantly with other symptomatic cold and flu remedies (vasoconstrictors, paracetamol-containing products). Use with caution in patients with Raynaud's disease, arterial hypertension, heart disease, arrhythmia, bradycardia, thyroid disorders, liver or kidney disease, acute hepatitis, glaucoma, chronic pulmonary diseases, prostate hypertrophy (due to risk of urinary retention), elderly individuals, increased blood coagulability, hemolytic anemia, chronic malnutrition, dehydration, or stenosing peptic ulcer. The risk of hepatotoxicity is increased in patients with alcoholic liver disease or those who abuse alcohol.

Cases of metabolic acidosis with high anion gap (high anion gap metabolic acidosis, HAGMA) due to 5-oxoproline (pyroglutamic) acidosis have been reported in patients with severe conditions such as severe renal failure, sepsis, malnutrition, or other sources of glutathione deficiency (e.g., chronic alcoholism), who were treated with paracetamol at therapeutic doses for prolonged periods or in combination with flucloxacillin. If HAGMA due to pyroglutamic acidosis is suspected, immediate discontinuation of paracetamol is recommended, along with careful monitoring. Measurement of urinary 5-oxoproline levels may be useful in identifying pyroglutamic acidosis as the underlying cause of HAGMA in patients with multiple risk factors.

The product contains: phenylephrine, which may provoke angina attacks; sucrose, which is contraindicated in patients with fructose intolerance, glucose-galactose malabsorption, or sucrose-isomaltase deficiency. Patients with known sugar intolerance should consult a physician before taking this medication. Use with caution in diabetic patients. May be harmful to teeth.

Consult a physician before use if you have: liver or kidney disease; are taking warfarin or similar anticoagulants; take analgesics daily for mild arthritis; or have bronchopulmonary diseases (asthma, emphysema, chronic bronchitis).

The drug may affect laboratory test results for blood glucose, uric acid, creatinine, and inorganic phosphates. Fecal occult blood testing may yield false-negative results.

In patients with severe infections (e.g., sepsis), where glutathione levels are reduced, paracetamol use increases the risk of metabolic acidosis. Symptoms include deep, rapid, or labored breathing, nausea, vomiting, and loss of appetite. In such cases, seek immediate medical attention.

It is not recommended to take this medication late in the day, as high doses of ascorbic acid may have a mild stimulating effect. Due to the stimulatory effect of ascorbic acid on corticosteroid hormone production, kidney function and blood pressure should be monitored.

Use with particular caution in patients with disorders of iron metabolism (hemochromatosis, hemosiderosis, thalassemia) and in those with a history of nephrolithiasis (risk of hyperoxaluria and oxalate deposition in the urinary tract after high-dose ascorbic acid intake).

Prolonged use of high doses of ascorbic acid may accelerate its own metabolism, potentially leading to paradoxical hypovitaminosis after discontinuation. Do not use concomitantly with other vitamin C-containing products. Absorption of ascorbic acid may be altered in intestinal motility disorders, enteritis, or reduced gastric secretion.

Use during pregnancy or breastfeeding.

The medication is contraindicated during pregnancy or breastfeeding. The effect of the drug on fertility has not been specifically studied. Preclinical studies have not revealed any particular effect of paracetamol on fertility when used at therapeutic doses. Adequate studies on the reproductive toxicity of phenylephrine and pheniramine in animals have not been conducted.

Ability to affect reaction speed when driving or operating machinery.

Since this medication may cause drowsiness and other adverse effects on the nervous system and vision, driving vehicles or operating complex machinery is not recommended during treatment.

Dosage and Administration

Dissolve the contents of the sachet in a glass of hot water (not boiling water) and drink. The medication may be taken every 3–4 hours, but no more than 3 sachets per day.

Maximum duration of use – 5 days.

Children.

The drug is contraindicated in children under 14 years of age.

Overdose.

Paracetamol. Within the first 24 hours, symptoms include pallor, nausea, vomiting, anorexia, and abdominal pain. After ingestion of large doses, disturbances in orientation, psychomotor agitation, dizziness, sleep disturbances, cardiac arrhythmias, pancreatitis, and hepatonecrosis may occur. The first sign of liver damage may be abdominal pain, which does not always appear within the first 12–48 hours and may develop later, up to 4–6 days after drug administration. Liver injury typically occurs within 72–96 hours after ingestion. Glucose metabolism disturbances and metabolic acidosis, as well as hemorrhages, may develop. With prolonged use of high doses, aplastic anemia, pancytopenia, agranulocytosis, neutropenia, leukopenia, and thrombocytopenia are possible.

In isolated cases, acute renal failure with tubular necrosis has been reported, even in the absence of severe liver damage. This condition may present with severe lumbar pain, hematuria, and proteinuria. Nephrotoxicity is possible: renal colic, interstitial nephritis, and capillary necrosis.

Ingestion of 10 g or more of paracetamol by adults, especially with alcohol, or more than 150 mg/kg body weight in children, may lead to hepatocellular necrosis, encephalopathy, hemorrhages, hypoglycemia, hepatic coma, and fatal outcome. In patients with risk factors (long-term treatment with carbamazepine, phenobarbital, phenytoin, primidone, rifampicin, St. John’s wort, or other drugs inducing liver enzymes; alcohol abuse; glutathione deficiency due to malnutrition, cystic fibrosis, HIV infection, fasting, or cachexia), ingestion of 5 g or more of paracetamol may cause liver damage.

In case of overdose, prompt medical assistance is required. The patient should be immediately transported to a hospital, even if early symptoms of overdose are absent. Symptoms may be limited to nausea and vomiting or may not reflect the severity of overdose or risk of organ damage. Activated charcoal should be administered within the first hour after overdose. Paracetamol plasma concentration should be measured 4 hours or later after ingestion (earlier concentrations are unreliable). N-acetylcysteine can be administered within 24 hours after paracetamol ingestion, but maximum efficacy is achieved when administered within the first 8 hours; after this, its effectiveness rapidly declines. If intravenous administration of N-acetylcysteine is required, it should be given according to the established dosing schedule. As an alternative, in the absence of vomiting, oral methionine may be used.

Phenylephrine. Symptoms include hyperhidrosis, psychomotor agitation or CNS depression, headache, dizziness, drowsiness, impaired consciousness, arrhythmia, tremor, hyperreflexia, seizures, nausea, vomiting, irritability, restlessness, arterial hypertension, and, in severe cases, coma. To counteract hypertensive effects, intravenous α-receptor blockers may be used; for seizures, diazepam is indicated.

Pheniramine. Anticholinergic-like symptoms occur: mydriasis, photophobia, dryness of skin and mucous membranes, hyperthermia, and intestinal atony. CNS depression leads to respiratory and cardiovascular system dysfunction (bradycardia, arterial hypotension, collapse). Symptoms due to the mutual potentiation of the anticholinergic effect of pheniramine and the sympathomimetic effect of phenylephrine include drowsiness, which may progress to agitation (especially in children) or CNS depression, visual disturbances, rash, persistent headache, nervousness, insomnia, hyperreflexia, irritability, circulatory disturbances, and bradycardia. There is no specific antidote for antihistamine overdose. Standard emergency care should be provided, including administration of activated charcoal, a saline laxative, and standard supportive measures for cardiopulmonary function. CNS stimulants are contraindicated; vasoconstrictors may be used to treat arterial hypotension.

Ascorbic acid. Symptoms include nausea, vomiting, or diarrhea (which resolve after discontinuation); bloating and abdominal pain, itching, skin rashes, and increased excitability. Doses exceeding 3000 mg may cause transient osmotic diarrhea and gastrointestinal disturbances, disturbances in zinc and copper metabolism, and myocardial dystrophy. With prolonged use of high doses, suppression of pancreatic islet function and glucosuria are possible. Overdose may lead to changes in renal excretion of ascorbic and uric acids during acetylation of urine, resulting in precipitation of oxalate stones.

Treatment is symptomatic: gastric lavage should be performed within the first 6 hours, and oral methionine or intravenous cysteamine or N-acetylcysteine should be administered within the first 8 hours.

Adverse reactions.

Skin and subcutaneous tissue disorders: rash, pruritus, dermatitis, urticaria, erythema multiforme, Stevens-Johnson syndrome, Lyell’s syndrome.

Immune system disorders: hypersensitivity reactions, including anaphylactic shock, angioedema.

Nervous system disorders: headache, dizziness, tremor, restlessness, nervousness, irritability, feeling of fear, insomnia, drowsiness, confusion, hallucinations, psychomotor agitation, disorientation, depressive state, paresthesia, tinnitus, in isolated cases – coma, seizures, dyskinesia, behavioral changes.

Respiratory system disorders: bronchospasm in patients sensitive to acetylsalicylic acid and NSAIDs.

Eye disorders: visual disturbances and accommodation disorders, mydriasis, increased intraocular pressure, dry eyes.

Gastrointestinal disorders: nausea, vomiting, heartburn, dry mouth, discomfort and abdominal pain, constipation, diarrhea, flatulence, anorexia, aphthae, hypersalivation, hemorrhage, mucosal irritation.

Hepatobiliary disorders: liver function abnormalities, hypertransaminasemia (usually without jaundice), hepatonecrosis (with high-dose administration).

Endocrine system disorders: hypoglycemia, up to hypoglycemic coma.

Blood and lymphatic system disorders: anemia, including hemolytic anemia, sulfhemoglobinemia and methemoglobinemia (cyanosis, dyspnea, chest pain), bruising or bleeding, thrombocytopenia, neutropenia, agranulocytosis, leukopenia, pancytopenia.

Renal and urinary disorders: nephrotoxicity, interstitial nephritis, capillary necrosis, dysuria, urinary retention and difficulty in urination, renal colic, renal failure.

Cardiac disorders: arterial hypertension, tachycardia, bradycardia, palpitations, arrhythmia, dyspnea, chest pain, angina attacks.

Metabolic and nutritional disorders: frequency unknown (cannot be estimated from available data) – metabolic acidosis with high anion gap.

Other: general weakness, malaise.

Unlike second-generation antihistamines, pheniramine use is not associated with QT interval prolongation or cardiac arrhythmia.

Description of selected adverse reactions.

Metabolic acidosis with high anion gap. Cases of metabolic acidosis with high anion gap as a result of pyroglutamic acidosis have been observed in patients with risk factors who used paracetamol (see section "Special precautions"). Pyroglutamic acidosis may occur due to low glutathione levels in these patients.

Reporting of adverse reactions after drug registration is of great importance. It enables continuous monitoring of the benefit-risk balance of the medicinal product. Healthcare professionals, pharmacists, patients, or their legal representatives are encouraged to report all suspected adverse reactions and lack of efficacy via the Automated Pharmacovigilance Information System at the following link: https://aisf.dec.gov.ua.

Shelf life. 2 years.

Storage conditions. Store at a temperature not exceeding 25 °C. Keep out of reach of children.

Packaging. 23 g in sachets, 5 or 10 sachets per carton.

Availability. Over-the-counter.

Manufacturer. Private Joint-Stock Company "Lekhim-Kharkiv".

Manufacturer's address and location of operations.
36 Severina Pototskoho Street, Kharkiv, Kharkiv Oblast, 61115, Ukraine.