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Antiviral / immunomodulator Pregnancy: §4.6, verbatim: 'Controlled trials monitoring foetal risk and impairment of fertility in humans are not available. It is not known if Imunovir is excreted in human milk. Therefore, Imunovir should not be administered during pregnancy or lactation unless the physician decides the benefits outweigh the potential risk. Although animal tests have shown no teratogenic effect, the use of Imunovir in women where pregnancy is suspected or confirmed should be avoided.'

Inosine pranobex

Brand names: Imunovir

Inosine pranobex is an orally administered antiviral and immunomodulatory agent used for mucocutaneous herpes simplex infections and, in specialist settings, subacute sclerosing panencephalitis.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Adults and the elderly, general regimen — §4.2 verbatim: 'The recommended dosage is 50mg/kg – 100mg/kg of body weight usually 3g/day up to a maximum of 4g/day, administered orally in 3-4 equally divided doses during waking hours.' READ THE PER-KILOGRAM FIGURE AS A DAILY TOTAL: the SPC equates 50–100 mg/kg to 'usually 3g/day up to a maximum of 4g/day' and then divides it into 3–4 doses, so it is 50–100 mg/kg/DAY, never a per-dose figure. INDICATION-SPECIFIC REGIMENS, §4.2 verbatim: mucocutaneous herpes simplex — '1 g administered orally 4 times daily, for 7 - 14 days'; genital warts — '1g administered orally 3 times daily, for 14-28 days as adjunctive therapy to podophyllin or carbon dioxide laser'; subacute sclerosing panencephalitis (SSPE) — '50-100mg/kg daily, up to a maximum of 3-4 g, in divided doses every 4 hours, with regular monitoring to evaluate patient status and requirement for extended treatment.' §4.2 also states: 'The weight of the patient and the severity of the disease are important factors in determining the dosage.'
Route: Oral. §4.2 verbatim: 'Oral use. To make ingestion easier, the tablets may be crushed and dissolved in a small amount of flavoured liquid at the time of administration.'
Frequency: General regimen: in 3–4 equally divided doses during waking hours. Mucocutaneous herpes simplex: 4 times daily for 7–14 days. Genital warts: 3 times daily for 14–28 days. SSPE: in divided doses every 4 hours.
Max: 4 g per day. §4.2, general adult/elderly regimen, verbatim: 'usually 3g/day up to a maximum of 4g/day'. For SSPE the SPC states its own ceiling: '50-100mg/kg daily, up to a maximum of 3-4 g'. The two indication regimens sit inside this ceiling (mucocutaneous herpes simplex 1 g four times daily = 4 g/day; genital warts 1 g three times daily = 3 g/day). No higher figure appears anywhere in the fetched SPC.
PAGE-IDENTITY MATCH: this page is 'Inosine pranobex' (oral antiviral / immunomodulator, brand Imunovir) and the fetched product is 'Imunovir 500mg Tablets' — the same active substance, the same route and the same UK brand, so the SPC serves the page directly. The dose above is the SPC's own general adult posology, with all three of the SPC's indication-specific regimens reproduced, because this is a drug-level page rather than a single-indication page. TABLET STRENGTH: the product fetched is a 500 mg tablet (from the product name), so the 3 g/day usual dose corresponds to the SPC's 3–4 divided doses of that tablet; the SPC itself does not restate tablet counts. §4.4 caution carried with the dose: Imunovir 'may be administered with caution in patients with a history of gout, hyperuricaemia, urolithiasis, or to patients with impaired renal function. During treatment, uric acid levels in these patients should be monitored closely.'

Paediatric dose

NO PAEDIATRIC DOSE EXISTS IN THE FETCHED LABEL. §4.2 'Children', verbatim and complete: 'No information is available in children.' The only other paediatric mention in the bundle is in §4.8, which reports that transient elevation of urine and serum uric acid is the one consistently observed drug-related effect 'in adults as well as paediatric population' — that is a safety observation, not a dose. dosePerKg is deliberately null: the adult 50–100 mg/kg figure is a DAILY total for adults and must not be fed to a paediatric weight calculator.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • §4.3, verbatim: 'Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.'
  • §4.3, verbatim: 'Imunovir should not be used where the patient is presently suffering from gout or has elevated uric acid blood levels.'
  • Not a contraindication but an excipient bar, §4.4, verbatim: 'Wheat starch in this medicine contains only very low levels of gluten regarded as gluten-free and is very unlikely to cause problems if you have coeliac disease. One tablet contains no more than 10.5 micrograms of gluten. If you have a wheat allergy (different from coeliac disease) you should not take this medicine.'

Side effects

  • §4.8 summary, verbatim: 'the only consistently observed drug-related side effects in adults as well as paediatric population is a transient elevation (usually remaining within normal range) of urine and serum uric acid levels, which usually return to baseline values a few days after the end of treatment.'
  • Very common (≥1/10): blood uric acid increased, urine uric acid increased.
  • Common (≥1/100 to <1/10): headache, vertigo, vomiting, nausea, epigastric discomfort, rash, pruritus, arthralgia, fatigue, malaise, blood urea increased, transaminases increased, blood alkaline phosphate increased.
  • Uncommon (≥1/1,000 to <1/100): nervousness, somnolence, insomnia, diarrhoea, constipation, polyuria.
  • Not known: angioedema, hypersensitivity, urticaria, anaphylactic reaction, dizziness, abdominal pain upper, erythema. §4.4 adds: 'In some people acute hypersensitivity reactions (urticaria, angioedema, anaphylaxis) may occur. Treatment with Imunovir should be withdrawn in these cases.'

Interactions

  • §4.5, verbatim: 'The drug should be used with caution with xanthine oxidase inhibitors or uricosuric agents, including diuretics.'
  • §4.5, verbatim: 'Imunovir may be administered after but not concomitantly with immunosuppressive agents, as there may be a pharmacokinetic influence on the desired therapeutic effects.'
  • §4.5, verbatim: 'Concomitant use with AZT increases AZT nucleotide formation through multiple mechanisms involving increased plasma AZT bioavailability and increased intracellular phosphorylation in human blood monocytes. As a result Imunovir increases the effect of AZT.'

Monitoring

  • §4.4, in patients with a history of gout, hyperuricaemia, urolithiasis or impaired renal function, verbatim: 'During treatment, uric acid levels in these patients should be monitored closely.'
  • §4.4, long-term treatment, verbatim: 'In the case of long term treatment, the serum and/or urine uric acid levels, liver function, blood count and renal functions should be checked on a regular basis in all patients. There is a possibility that ureteric and biliary calculi may occur when patients receive long term treatment.'
  • §4.2, SSPE, verbatim: dosing is given 'with regular monitoring to evaluate patient status and requirement for extended treatment.'
  • §4.4: withdraw treatment if acute hypersensitivity reactions (urticaria, angioedema, anaphylaxis) occur.

Clinical monograph

How it works

It is thought to act by enhancing host cell-mediated immune responses and impairing viral replication, giving combined antiviral and immunostimulant effects.

Prescribing in practice

  • Because it raises serum and urinary uric acid, it should be used with caution in patients with gout, hyperuricaemia or a history of urolithiasis.
  • Use with caution in renal impairment, where uric acid handling is reduced.
  • Evidence of clinical benefit is limited, so it is generally reserved for selected indications rather than first-line use.

Monitoring

Monitor serum uric acid and renal function during prolonged or repeated courses, particularly in those predisposed to gout or stones.

Counselling the patient

  • Maintain a good fluid intake while taking this medicine.
  • Report joint pain, swelling or loin pain that could suggest gout or kidney stones.
  • Take the medicine for the full course as directed even if symptoms settle.

Evidence & guidelines

Its place in therapy is limited; consult the SPC and current prescribing references for licensed indications and cautions.

Reference: Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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