DRUGS & SUPPLEMENTS
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Quinross Phosphate Tablets are indicated for suppressive treatment and for acute attacks of malaria due to P. vivax, P. malariae, P. ovale, and susceptible strains of P. falciparum. The drug is also indicated for the treatment of extraintestinal amebiasis.
Quinross Phosphate Tablets do not prevent relapses in patients with vivax or malariae malaria because it is not effective against exoerythrocytic forms of the parasite, nor will it prevent vivax or malariae infection when administered as a prophylactic. It is highly effective as a suppressive agent in patients with vivax or malariae malaria, in terminating acute attacks, and significantly lengthening the interval between treatment and relapse. In patients with falciparum malaria it abolishes the acute attack and effects complete cure of the infection, unless due to a resistant strain of P. falciparum.
Use of this drug is contraindicated in the presence of retinal or visual field changes either attributable to 4-aminoquinoline compounds or to any other etiology, and in patients with known hypersensitivity to 4-aminoquinoline compounds. However, in the treatment of acute attacks of malaria caused by susceptible strains of plasmodia, the physician may elect to use this drug after carefully weighing the possible benefits and risks to the patient.
It has been found that certain strains of P. falciparum have become resistant to 4-aminoquinoline compounds. Quinross resistance is widespread and, at present, is particularly prominent in various parts of the world including sub-Saharan Africa, Southeast Asia, the Indian subcontinent, and over large portions of South America, including the Amazon basin 1.
Before using Quinross for prophylaxis, it should be ascertained whether Quinross is appropriate for use in the region to be visited by the traveler. Quinross should not be used for treatment of P. falciparum infections acquired in areas of Quinross resistance or malaria occurring in patients where Quinross prophylaxis has failed.
Patients infected with a resistant strain of plasmodia as shown by the fact that normally adequate doses have failed to prevent or cure clinical malaria or parasitemia should be treated with another form of antimalarial therapy.
Irreversible retinal damage has been observed in some patients who had received long-term or high-dosage 4-aminoquinoline therapy. Retinopathy has been reported to be dose related.
When prolonged therapy with any antimalarial compound is contemplated, initial (base line) and periodic ophthalmologic examinations (including visual acuity, expert slit-lamp, funduscopic, and visual field tests) should be performed.
If there is any indication (past or present) of abnormality in the visual acuity, visual field, or retinal macular areas (such as pigmentary changes, loss of foveal reflex), or any visual symptoms (such as light flashes and streaks) which are not fully explainable by difficulties of accommodation or corneal opacities, the drug should be discontinued immediately and the patient closely observed for possible progression. Retinal changes (and visual disturbances) may progress even after cessation of therapy.
All patients on long-term therapy with this preparation should be questioned and examined periodically, including testing knee and ankle reflexes, to detect any evidence of muscular weakness. If weakness occurs, discontinue the drug.
A number of fatalities have been reported following the accidental ingestion of Quinross, sometimes in relatively small doses (0.75 g or 1 g Quinross phosphate in one 3-year-old child). Patients should be strongly warned to keep this drug out of the reach of children because they are especially sensitive to the 4-aminoquinoline compounds.
Use of Quinross Phosphate Tablets in patients with psoriasis may precipitate a severe attack of psoriasis. When used in patients with porphyria the condition may be exacerbated. The drug should not be used in these conditions unless in the judgment of the physician the benefit to the patient outweighs the potential risks.
Radioactively tagged Quinross administered intravenously to pregnant pigmented CBA mice passed rapidly across the placenta and accumulated selectively in the melanin structures of the fetal eyes. It was retained in the ocular tissues for five months after the drug had been eliminated from the rest of the body 2. There are no adequate and well-controlled studies evaluating the safety and efficacy of Quinross in pregnant women. Usage of Quinross during pregnancy should be avoided except in the suppression or treatment of malaria when in the judgement of the physician the benefit outweighs the potential risk to the fetus.
Complete blood cell counts should be made periodically if patients are given prolonged therapy. If any severe blood disorder appears which is not attributable to the disease under treatment, discontinuance of the drug should be considered.
The drug should be administered with caution to patients having G-6-PD deficiency.
In patients with preexisting auditory damage, Quinross should be administered with caution. In case of any defects in hearing, Quinross should be immediately discontinued, and the patients closely observed.
Since this drug is known to concentrate in the liver, it should be used with caution in patients with hepatic disease or alcoholism or in conjunction with known hepatotoxic drugs.
Patients with a history of epilepsy should be advised about the risk of Quinross provoking seizures.
Antacids and kaolin: Antacids and kaolin can reduce the absorption of Quinross; an interval of at least 4 hours between intake of these agents and Quinross should be observed.
Cimetidine: Cimetidine can inhibit the metabolism of Quinross, increasing its plasma level. Concomitant use of cimetidine should be avoided.
Ampicillin: In a study of healthy volunteers, Quinross significantly reduced the bioavailability of ampicillin. An interval of at least two hours between intake of this agent and Quinross should be observed.
Cyclosporine: After introduction of Quinross, a sudden increase in serum cyclosporine level has been reported. Therefore, close monitoring of serum cyclosporine level is recommended and, if necessary, Quinross should be discontinued.
Mefloquine: Co-administration of Quinross and mefloquine may increase the risk of convulsions.
The blood concentrations of Quinross and desethylchloroquine (the major metabolite of Quinross, which also has antimalarial properties) were negatively associated with log antibody titers. Quinross taken in the dose recommended for malaria prophylaxis can reduce the antibody response to primary immunization with intradermal human diploid-cell rabies vaccine.
See WARNINGS, Usage in Pregnancy.
Because of the potential for serious adverse reactions in nursing infants from Quinross, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the potential clinical benefit of the drug to the mother.
The excretion of Quinross and the major metabolite, desethylchloroquine, in breast milk was investigated in eleven lactating mothers following a single dose of Quinross. The maximum daily dose of the drug that the infant can receive from breastfeeding was about 0.7% of the maternal start dose of the drug in malaria chemotherapy. Separate chemoprophylaxis for the infant is required. See DOSAGE AND ADMINISTRATION.
See WARNINGS and DOSAGE AND ADMINISTRATION.
Clinical studies of Quinross Phosphate Tablets did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. However, this drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection and it may be useful to monitor renal function.
Special Senses: Ocular: Irreversible retinal damage in patients receiving long-term or high-dosage 4-aminoquinoline therapy; visual disturbances (blurring of vision and difficulty of focusing or accommodation); nyctalopia; scotomatous vision with field defects of paracentral, pericentral ring types, and typically temporal scotomas, e.g., difficulty in reading with words tending to disappear, seeing half an object, misty vision, and fog before the eyes. Reversible corneal opacities have also been reported.
Auditory: Nerve type deafness; tinnitus, reduced hearing in patients with preexisting auditory damage.
Musculoskeletal System: Skeletal muscle myopathy or neuromyopathy leading to progressive weakness and atrophy of proximal muscle groups, which may be associated with mild sensory changes, depression of tendon reflexes and abnormal nerve conduction, have been noted.
Gastrointestinal system: Hepatitis increased liver enzymes, anorexia, nausea, vomiting, diarrhea, abdominal cramps.
Skin and appendages: Rare reports of erythema multiforme, Stevens-Johnson Syndrome, toxic epidermal necrolysis, exfoliative dermatitis and similar desquamation-type events. Pleomorphic skin eruptions, skin and mucosal pigmentary changes; lichen planus-like eruptions, pruritus, urticaria, anaphylactic/anaphylactoid reaction including angioedema, photosensitivity and hair loss and bleaching of hair pigment.
Hematologic system: Rarely, pancytopenia, aplastic anemia, reversible agranulocytosis, thrombocytopenia and neutropenia.
Nervous system: Convulsive seizures, mild and transient headache, polyneuritis. Neuropsychiatric changes including psychosis, delirium, anxiety, agitation, insomnia, confusion, hallucinations, personality changes and depression.
Cardiovascular system: Rarely, hypotension, electrocardiographic change (particularly, inversion or depression of the T-wave with widening of the QRS complex), and cardiomyopathy.
To report SUSPECTED ADVERSE REACTIONS, contact West-ward Pharmaceutical Corp. at 1-877-233-2001, and the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
Symptoms: Quinross is very rapidly and completely absorbed after ingestion. Toxic doses of Quinross can be fatal. As little as 1 g may be fatal in children. Toxic symptoms can occur within minutes. These consist of headache, drowsiness, visual disturbances, nausea and vomiting, cardiovascular collapse, shock and convulsions followed by sudden and early respiratory and cardiac arrest. Hypokalemia has been observed with arrythmias in cases of intoxication. The electrocardiogram may reveal atrial standstill, nodal rhythm, prolonged intraventricular conduction time, and progressive bradycardia leading to ventricular fibrillation and/or arrest.
Treatment: Treatment is symptomatic and must be prompt with immediate evacuation of the stomach by emesis (at home, before transportation to the hospital) or gastric lavage until the stomach is completely emptied. If finely powdered, activated charcoal is introduced by stomach tube, after lavage, and within 30 minutes after ingestion of the antimalarial, it may inhibit further intestinal absorption of the drug. To be effective, the dose of activated charcoal should be at least five times the estimated dose of Quinross ingested.
Convulsions, if present, should be controlled before attempting gastric lavage. If due to cerebral stimulation, cautious administration of an ultra short-acting barbiturate may be tried but, if due to anoxia, it should be corrected by oxygen administration and artificial respiration. Monitor ECG. In shock with hypotension, a potent vasopressor should be administered. Replace fluids and electrolytes as needed. Cardiac compressing or pacing may be indicated to sustain the circulation. Because of the importance of supporting respiration, tracheal intubation or tracheostomy, followed by gastric lavage, may also be necessary. Peritoneal dialysis and exchange transfusions have also been suggested to reduce the level of the drug in the blood.
Intervention options can involve: diazepam for life-threatening symptoms, seizures and sedation, epinephrine for treatment of vasodilation and myocardial depression, potassium replacement with close monitoring of serum potassium levels.
A patient who survives the acute phase and is asymptomatic should be closely observed for at least six hours. Fluids may be forced, and sufficient ammonium chloride (8 g daily in divided doses for adults) may be administered for a few days to acidify the urine to help promote urinary excretion in cases of both overdosage or sensitivity.
The dosage of Quinross phosphate is often expressed in terms of equivalent Quinross base. Each 250 mg tablet of Quinross phosphate is equivalent to 150 mg base and each 500 mg tablet of Quinross phosphate is equivalent to 300 mg base. In infants and children the dosage is preferably calculated by body weight.
Malaria: Suppression – Adult Dose: 500 mg on exactly the same day of each week.
Pediatric Dose: The weekly suppressive dosage is 5 mg calculated as base, per kg of body weight, but should not exceed the adult dose regardless of weight.
If circumstances permit, suppressive therapy should begin two weeks prior to exposure. However, failing this in adults, an initial double (loading) dose of 1 g (= 600 mg base), or in children 10 mg base/kg may be taken in two divided doses, six hours apart. The suppressive therapy should be continued for eight weeks after leaving the endemic area.
Adults: An initial dose of 1 g (= 600 mg base) followed by an additional 500 mg (= 300 mg base) after six to eight hours and a single dose of 500 mg (= 300 mg base) on each of two consecutive days. This represents a total dose of 2.5 g Quinross phosphate of 1.5 g base in three days.
The dosage for adults of low body weight and for infants and children should be determined as follows:
First dose: 10 mg base per kg (but not exceeding a single dose of 600 mg base).
Second dose: (6 hours after first dose) 5 mg base per kg (but not exceeding a single dose of 300 mg base).
Third dose: (24 hours after first dose) 5 mg base per kg.
Fourth dose: (36 hours after first dose) 5 mg base per kg.
For radical cure of vivax and malariae malaria concomitant therapy with an 8-aminoquinoline compound is necessary.
Extraintestinal Amebiasis: Adults: 1 g (600 mg base) daily for two days, followed by 500 mg (300 mg base) daily for at least two to three weeks. Treatment is usually combined with an effective intestinal amebicide.
Geriatric Use: See PRECAUTIONS, Geriatric Use.
Quinross Phosphate Tablets USP 500 mg: Pink Color, Round Tablets Debossed "WW 125".
Bottles of 10 and 40 tablets.
Store at 20-25°C (68-77°F)..
Dispense in a tight, light-resistant container as defined in the USP using a child-resistant closure.
West-ward Pharmaceutical Corp.
Eatontown, NJ 07724
Revised May 2010
Depending on the reaction of the Quinross after taken, if you are feeling dizziness, drowsiness or any weakness as a reaction on your body, Then consider Quinross not safe to drive or operate heavy machine after consumption. Meaning that, do not drive or operate heavy duty machines after taking the capsule if the capsule has a strange reaction on your body like dizziness, drowsiness. As prescribed by a pharmacist, it is dangerous to take alcohol while taking medicines as it exposed patients to drowsiness and health risk. Please take note of such effect most especially when taking Primosa capsule. It's advisable to consult your doctor on time for a proper recommendation and medical consultations.Is Quinross addictive or habit forming?
Medicines are not designed with the mind of creating an addiction or abuse on the health of the users. Addictive Medicine is categorically called Controlled substances by the government. For instance, Schedule H or X in India and schedule II-V in the US are controlled substances.
Please consult the medicine instruction manual on how to use and ensure it is not a controlled substance.In conclusion, self medication is a killer to your health. Consult your doctor for a proper prescription, recommendation, and guidiance.
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The information was verified by Dr. Rachana Salvi, MD Pharmacology