Formulary
Phenindione: Indications, Dosing, Side Effects and Interactions
Phenindione clinical drug profile including indications, dosing, side effects, cautions and interactions.
MedNext Academy | 3 min read
Phenindione: Indications, Dosing, Side Effects and Interactions
Phenindione clinical drug profile including indications, dosing, side effects, cautions and interactions.
Indications and dose
**Prophylaxis of embolisation in rheumatic heart disease and atrial fibrillation,Prophylaxis after insertion of prosthetic heart valve,Prophylaxis and treatment of venous thrombosis and pulmonary embolism**
- **Adult** (By Mouth): Initially 200 mg on day 1, then 100 mg on day 2, then, adjusted according to response; maintenance 50-150 mg daily.
Cautions
K antagonists Bacterial endocarditis (use only if warfarin otherwise indicated); conditions in which risk of bleeding is increased; history of gastro-intestinal bleeding; hyperthyroidism; hypothyroidism; peptic ulcer; recent ischaemic stroke; recent surgery; uncontrolled hypertension Cautions, further information Elderly Screening Tool of Older Persons' potentially inappropriate Prescriptions (STOPP) criteria to aid medication reviews (see Prescribing in the elderly for information). Potentially inappropriate: with concurrent significant bleeding risk, such as uncontrolled severe hypertension, bleeding diathesis, or recent non-trivial spontaneous bleeding (high risk of bleeding) as part of dual therapy with an antiplatelet agent in patients with stable coronary, cerebrovascular, or peripheral arterial disease, without a clear indication for anticoagulant therapy (no added benefit) for first deep venous thrombosis without continuing provoking risk factors (e.g. thrombophilia) for longer than 6 months (no proven added benefit) for first pulmonary embolus without continuing provoking risk factors for longer than 12 months (no proven added benefit)
Contraindications
K antagonists Avoid use within 48 hours postpartum; haemorrhagic stroke; significant bleeding
Side effects
K antagonists Common or very common Haemorrhage Rare or very rare Alopecia; nausea; vomiting Frequency not known Blue toe syndrome; CNS haemorrhage; diarrhoea; fever; haemothorax; jaundice; pancreatitis; skin necrosis (increased risk in patients with protein C or protein S deficiency); skin reactions Side-effects For phenindione Frequency not known Agranulocytosis; albuminuria; eosinophilia; hepatitis; increased leucocytes; kidney injury; leucopenia; lymphadenopathy; pancytopenia; renal tubular necrosis; taste altered; urine discolouration
Interactions
**Other interactions (10):**
- Fibrinolytic drugs such as streptokinase and alteplase are contra-indicated in patients receiving Dindevan.
- Drugs which should be avoided if possible The following examples should be avoided, or administered with caution with increased clinical and laboratory monitoring: - Clopidogrel - NSAIDs (including...
- Examples of drugs which potentiate the effect of Dindevan - ACTH, allopurinol, amitriptyline/nortriptyline, Cimetidine, Dextropropoxyphene, Glucagon, Hepato-toxic drugs, Phenformin, Thyroid...
- Examples of drugs which antagonise the effect of Dindevan Barbiturates, Carbamazepine; Griseofulvin, Phenytoin.
- Other drug interactions Broad spectrum antibiotics may potentiate the effect of Dindevan by reducing the gut flora which produce vitamin K.
- Similarly, orlistat may reduce absorption of vitamin K.
Pregnancy
K antagonists Should not be given in the first trimester of pregnancy. Warfarin, acenocoumarol, and phenindione cross the placenta with risk of congenital malformations, and placental, fetal, or neonatal haemorrhage, especially during the last few weeks of pregnancy and at delivery. Therefore, if at all possible, they should be avoided in pregnancy, especially in the first and third trimesters (difficult decisions may have to be made, particularly in women with prosthetic heart valves, atrial fibrillation, or with a history of recurrent venous thrombosis or pulmonary embolism). Stopping these drugs before the sixth week of gestation may largely avoid the risk of fetal abnormality.
Breast feeding
Avoid. Risk of haemorrhage; increased by vitamin K deficiency.
Hepatic impairment
K antagonists In general, manufacturers advise caution in mild to moderate impairment; avoid in severe impairment.
Renal impairment
Caution in mild to moderate impairment; avoid in severe impairment. M Dose adjustments Dose reduction may be required in mild to moderate impairment. M
Medicinal forms
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
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