How to use Pentoxil
Take this medication by mouth with food, usually 3 times daily or as directed by your doctor.
Do not crush or chew this medication. Doing so can release all of the drug at once, increasing the risk of side effects. Also, do not split the tablets unless they have a score line and your doctor or pharmacist tells you to do so. Swallow the whole or split tablet without crushing or chewing.
Dosage is based on your medical condition and response to treatment.
Use this medication regularly in order to get the most benefit from it. To help you remember, take it at the same times each day. It is important to continue taking this medication even if you feel well. Do not stop this medication without consulting your doctor. Improvement in symptoms can occur in 2-4 weeks, but it may take up to 8 weeks to get the full benefit.
Tell your doctor if your condition persists or worsens.
Dictionary Entries near Pentoxil
Cite this Entry
“Pentoxil.” The Merriam-Webster.com Medical Dictionary, Merriam-Webster Inc., https://www.merriam-webster.com/medical/Pentoxil. Accessed 27 December 2019.
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1.5 Appearance, Color, and Odor
Pentoxil is a white, or almost white, crystalline or microcrystalline powder, which has a bitter taste and only a slight characteristic odor .
1.6 Uses and applications
Pentoxil decreases the viscosity of blood, and thereby improves its flow. This increased blood flow helps patients with peripheral arterial disease to obtain better circulation and oxygen delivery to vital tissues . The drug was first introduced in Germany in 1972 (by Albert-Rouseel), in France in 1974 (by Hoechst), in the United Kingdom in 1975 (Hoechst), in Italy in 1976 (by Hoechst), and in Japan in 1977 (by Hoechst) . Pentoxil was the first drug approved for the treatment of intermittent claudication .
The therapeutic indication for Pentoxil were for intermittent claudication secondary to chronic occlusive vascular disease, Reynould's syndromes, and transient ischaemic attacks . Pentoxil can also be used also to lower blood level of the cytokine called tumor necrosis factor . The usual dose is 400 mg three times daily per oral, reducing to 400 mg twice daily if adverse effects become troublesome. Beneficial effects may not be evident until after 2 to 6 weeks of treatment .
Pentoxil is contraindicated for patients who have had a recent brain hemorrhage. The compound is structurally related to caffeine and theophylline, and should therefore be used with caution in patients sensitive to these substances . The drug is not used in neonatals and lactating women owing to its secretion in breast milk .
The concomitant use of Pentoxil and aspirin has been reported to cause increase bleeding. Pentoxil may occasionally enhance the effect of hypotensive drugs, and its use may require reduction of their dose. Parentally administered Pentoxil has been reported to enhance the hypoglycaemic effects of insulin and oral hypoglycaemic drugs . Cimetidine concomitantly administrated with Pentoxil caused a reduction in the total apparent clearance of Pentoxil .
Carl P. Weiner MD, MBA, FACOG, Clifford Mason PhD, in Drugs for Pregnant and Lactating Women (Third Edition) , 2019
Pigmented purpuric dermatoses
Successful treatment with Pentoxil causes decrease in expression of ICAM-I on endothelial cells in and around PPD lesions, resulting in decreased exudation of inflammatory cells from capillaries into the surrounding perivascular tissue and also reduced TNF mediated extravasations. Pentoxil being economical, easily available and devoid of serious side-effects should be considered for use in Schamberg's disease, a type of PPD; some advocate it as first line therapy.
Bleeding has been reported in patients treated with Pentoxil extended-release tablets with or without concomitant NSAIDs, anticoagulants, or platelet aggregation inhibitors.
Increased prothrombin time has been reported in patients concomitantly treated with Pentoxil and vitamin K antagonists. Monitoring of anticoagulant activity in these patients is recommended when Pentoxil is introduced or the dose is changed.
Concomitant administration of Pentoxil extended-release tablets and theophylline-containing drugs leads to increased theophylline levels and theophylline toxicity in some individuals. Monitor theophylline levels when starting Pentoxil extended-release tablets or changing dose.
Concomitant administration of strong CYP1A2 inhibitors (including e.g., ciprofloxacin or fluvoxamine) may increase the exposure to Pentoxil (see ADVERSE REACTIONS).
Pentoxil extended-release tablets have been used concurrently with antihypertensive drugs, beta blockers, digitalis, diuretics, and antiarrhythmics, without observed problems. Small decreases in blood pressure have been observed in some patients treated with Pentoxil extended-release tablets; periodic systemic blood pressure monitoring is recommended for patients receiving concomitant antihypertensive therapy. If indicated, dosage of the antihypertensive agents should be reduced.
Postmarketing cases of increased anticoagulant activity have been reported in patients concomitantly treated with Pentoxil and vitamin K antagonists. Monitoring of anticoagulant activity in these patients is recommended when Pentoxil is introduced or the dose is changed.
Concomitant administration with cimetidine is reported to increase the average steady state plasma concentration of Pentoxil (
25%) and the Metabolite I (
Mode of Action
Pentoxil and its metabolites improve the flow properties of blood by decreasing its viscosity. In patients with chronic peripheral arterial disease, this increases blood flow to the affected microcirculation and enhances tissue oxygenation. The precise mode of action of Pentoxil and the sequence of events leading to clinical improvement are still to be defined. Pentoxil administration has been shown to produce dose-related hemorrheologic effects, lowering blood viscosity, and improving erythrocyte flexibility. Leukocyte properties of hemorrheologic importance have been modified in animal and in vitro human studies. Pentoxil has been shown to increase leukocyte deformability and to inhibit neutrophil adhesion and activation. Tissue oxygen levels have been shown to be significantly increased by therapeutic doses of Pentoxil in patients with peripheral arterial disease.
Trental, Tarontal, Elorgan, Terental, Torental, Erytral, Lentrin, Reotal, Zumavastal
Generally Pentoxil is available as tablet, film-coated tablet, sugar-coated tablet or caplet, each containing 100, 200 or 400 mg of drug .
Follow your doctor's instructions about any restrictions on food, beverages, or activity.
If you also take a blood thinner such as warfarin (Coumadin, Jantoven), you may need more frequent "INR" or prothrombin time tests to measure your blood-clotting time.
Other drugs may interact with Pentoxil, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.
Pharmacokinetics and Metabolism
After oral administration in aqueous solution Pentoxil is almost completely absorbed. It undergoes a first-pass effect and the various metabolites appear in plasma very soon after dosing. Peak plasma levels of the parent compound and its metabolites are reached within 1 hour. The major metabolites are Metabolite I (1--3,7-dimethylxanthine) and Metabolite V (1--3,7-dimethylxanthine), and plasma levels of these metabolites are 5 and 8 times greater, respectively, than Pentoxil.
Following oral administration of aqueous solutions containing 100 mg to 400 mg of Pentoxil, the pharmacokinetics of the parent compound and Metabolite I are dose-related and not proportional (non-linear), with half-life and area under the blood-level time curve (AUC) increasing with dose. The elimination kinetics of Metabolite V are not dose-dependent. The apparent plasma half-life of Pentoxil varies from 0.4 to 0.8 hours and the apparent plasma half-lives of its metabolites vary from 1 to 1.6 hours. There is no evidence of accumulation or enzyme induction (Cytochrome P450) following multiple oral doses.
Excretion is almost totally urinary; the main biotransformation product is Metabolite V. Essentially no parent drug is found in the urine. Despite large variations in plasma levels of parent compound and its metabolites, the urinary recovery of Metabolite V is consistent and shows dose proportionality. Less than 4% of the administered dose is recovered in feces. Food intake shortly before dosing delays absorption of an immediate-release dosage form but does not affect total absorption. The Pentoxil AUC was increased and elimination rate decreased in an older population (60 to 68 years, n = 6) compared to younger indiv >
After administration of the 400 mg extended-release Pentoxil tablet, plasma levels of the parent compound and its metabolites reach their maximum within 2 to 4 hours and remain constant over an extended period of time. Coadministration of Pentoxil extended-release tablets with meals resulted in an increase in mean AUC and C max of about 1.1 and 1.3 fold for Pentoxil, respectively. C max for Metabolite I also increased about 1.2 fold. The extended-release of Pentoxil from the tablet eliminates peaks and troughs in plasma levels for improved gastrointestinal tolerance.
Patients with Hepatic Impairment
In patients with mild to moderate liver impairment AUC and C max of Pentoxil increased 6.5 and 7.5 fold, respectively, after a single 400 mg dose of Pentoxil extended-release tablets. AUC and C max of the active Metabolite I also increased 6.9 and 8.2 fold, respectively, in hepatic impaired subjects.
Pentoxil extended-release tablets have not been studied in patients with severe hepatic failure.
Patients with Renal Impairment
In patients with mild, moderate, or severe renal impairment the exposure to Pentoxil and its active Metabolite I are not increased. In contrast, AUC 0-tss and C max of the active Metabolite V in patients with mild to moderate renal impairment increased 2.4 and 2.1 fold, respectively, with a 400 mg T >0-tss and C max of the active Metabolite V increased 12.9 and 10.6 fold, respectively, with a 400 mg Pentoxil extended-release tablets TID regimen. The increase in exposure to Metabolite V is only slightly smaller in both renal impairment groups if Pentoxil extended-release tablets are administered BID.
What Is Pentoxil?
Pentoxil causes changes in your blood that help improve blood flow. This also helps your blood carry oxygen to your tissues and organs.
Pentoxil is used to improve blood flow and reduce certain symptoms of a condition called intermittent claudication (IN-ter-MIT-ent KLOD-ih-KAY-tion). Pentoxil is not a cure for this condition.
Pentoxil may also be used for purposes not listed in this medication guide.
You should not use this medicine if you have recently had any type of bleeding in your brain or the retina of your eye.
You should not use this medicine if you are allergic to Pentoxil, or if you are allergic to caffeine or theophylline (Elixophyllin, Theo-24, Theo-Dur, Slo-Bid, Theochron, Theolair, Uniphyl, and others).
You also should not use Pentoxil if you have recently had any type of bleeding in your brain or the retina of your eyes.
To make sure Pentoxil is safe for you, tell your doctor if you have:
- coronary artery disease (hardened arteries);
- liver or kidney disease;
- heart disease;
- a history of bleeding in your brain or inside your eyes;
- history of heart attack or stroke;
- a stomach or intestinal ulcer;
- if you have recently had surgery;
- if you are also using theophylline; or
- if you use medicine to treat or prevent blod clots.
It is not known whether Pentoxil will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medicine.
Pentoxil can pass into breast milk and may harm a nursing baby. You should not breast-feed while you are using Pentoxil.
What is the dosage for Trental?
The recommended dose of Pentoxil is 400 mg three times daily with meals. The dose may be reduced to 400 mg twice daily to reduce adverse effects.
What do I need to tell my doctor BEFORE I take Pentoxil?
- If you have an allergy to Pentoxil or any other part of Pentoxil.
- If you are allergic to any drugs like this one, any other drugs, foods, or other substances. Tell your doctor about the allergy and what signs you had, like rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.
- If you have had a recent bleeding problem in your brain or in the retina of your eye.
- If you are breast-feeding or plan to breast-feed.
This is not a list of all drugs or health problems that interact with Pentoxil.
Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take Pentoxil with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.
Besides its use as an adjuvant therapy in psoriasis, it has been suggested that Pentoxil counteracts many of the unwanted effects of cyclosporine on red blood cells, platelets and coagulation factors. Abnormal metabolism of triglyceride is common in psoriatic patients and is exaggerated after cyclosporine therapy. Pentoxil possibly reduces serum triglycerides, so it seems sensible to use Pentoxil in combination with cyclosporine to reduce the side-effects of the later. Thus, Pentoxil seems to be a promising well-tolerated and safe adjuvant drug for use in psoriasis.
Teratogenicity studies have been performed in rats and rabbits using oral doses up to 576 mg/kg and 264 mg/kg, respectively. On a weight basis, these doses are 24 and 11 times the maximum recommended human daily dose (MRHD); on a body-surface-area basis, they are 4.2 and 3.5 times the MRHD. No evidence of fetal malformation was observed. Increased resorption was seen in rats of the 576 mg/kg group. There are no adequate and well controlled studies in pregnant women. Pentoxil extended-release tablets should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.