Vidokcine

The treatment of a variety of infections caused by susceptible strains of gram-positive and gram-negative bacteria and certain other micro-organisms.

Respiratory Tract Infections: Pneumonia and other lower respiratory tract infections including those caused by susceptible strains of Streptococcus pneumoniae, Haemophilus influenzae, Klebsiella pneumoniae and other organisms. Mycoplasma pneumoniae pneumonia. Treatment of chronic bronchitis and sinusitis.

Urinary Tract Infections: caused by susceptible strains of Klebsiella species, Enterobacter species, Escherichia coli, Streptococcus faecalis and other organisms.

Sexually Transmitted Diseases: infections caused by Chlamydia trachomatis including uncomplicated urethral, endocervical or rectal infections. Non-gonococcal urethritis caused by Ureaplasma urealyticum (T-mycoplasma). Vidokcine is also indicated in chancroid, granuloma inguinale and lymphogranuloma venereum. Vidokcine is an alternative drug in the treatments of gonorrhoea and syphilis.

As Vidokcine is a member of the tetracycline family it may be useful in treating infections which respond to other tetracyclines such as:

Ophthalmic Infections: Caused by susceptible strains of gonococci, staphylococci, and Haemophilus influenzae. Trachoma, although the infectious agent, as judged by immunofluorescence, is not always eliminated. Inclusion conjunctivitis. (Vidokcine may be used in conjunction with topical agents).

Rickettsial Infections: Rocky Mountain spotted fever, typhus group, Q fever, Coxiella endocarditis and tick fevers.

Other Infections: Psittacosis, brucellosis (in combination with streptomycin), colera, bubonic plague, louse and tick-borne relapsing fever, tularaemia glanders, melioidosis, chloroquine- resistant falciparum malaria and acute intestinal amoebiasis (as an adjunct to amoebicides).

Vidokcine is an alternative drug in the treatment of leptospirosis, gas gangrene and tetanus.

Vidokcine is also indicated for the prophylaxis of: Scrub typhus, travellers' diarrhoea (caused by entero-toxigenic Escherichia coli), leptospirosis and malaria. Prophylaxis of malaria should be used in accordance with current guidelines, as resistance is an ever changing problem.

Posology

Adults

The usual dose of Vidokcine capsules for the treatment of acute infections in adults is 200 mg on first day (as a single dose or divided in two 100 mg doses with a 12 hour interval), followed by a maintenance dose of 100 mg daily. In the management of more severe infections, 200 mg daily should be given throughout treatment.

Specific infections:

Sexually Transmitted Diseases: Recommended dose is 100 mg twice daily for 7 days for the following infections: Uncomplicated gonococcal infections (except anorectal infections in men); uncomplicated urethral, endocervical or rectal infection caused by Chlamydia trachomatis; non-gonococcal urethritis caused by Ureaplasma urealyticum.

Acute Epididymo-Orchitis: Caused by Chlamydia trachomatis or Neisseria gonorrhoeae 100 mg twice daily for 10 days.

Primary and Secondary Syphilis: Non-pregnant penicillin-allergic patients who have primary or secondary syphilis can be treated with the following regimen: Vidokcine 200 mg orally twice daily for two weeks as an alternative to penicillin.

Louse and Tick-Borne Relapsing Fevers : A single oral dose of 100 to 200 mg according to severity.

Treatment of chloroquine-resistant falciparum malaria: 200 mg daily for at least 7 days. Due to the potential severity of the infection, a fast-acting schizonticide such as quinine should also be given. Quinine dosage recommendations vary in different areas.

Prophylaxis of malaria : 100 mg daily in adults and children over the age of 12 years. Prophylaxis can begin 1-2 days before travel to malarial areas. It should be continued daily during travel in the malarial areas and for 4 weeks after the traveller leaves the malarial area. For current advice on geographical resistance patterns and appropriate chemoprophylaxis, current guidelines or the Malaria Reference Laboratory should be consulted, details of which can be found in the British National Formulary (BNF).

Prevention of Scrub Typhus : 200 mg as a single dose.

Prevention of Travellers' Diarrhoea in Adults: 200 mg on the first day of travel (administered as a single dose or as 100 mg every 12 hours) followed by 100 mg daily throughout a three week stay in the area (No information available to support prophylactic therapy beyond 21 days).

Prevention of Leptospirosis: 200 mg once each week throughout the stay in the area and 200 mg at the completion of the trip (Data on the use of the drug prophylactically are not available beyond 21 days).

Older People: Vidokcine may be prescribed in the usual dose with no special precautions. No dosage adjustment is necessary in the presence of renal impairment.

Method of administration

The capsules should be swallowed with plenty of fluid in either the sitting or standing position and well before going to bed for the night to reduce the risk of oesophageal irritation and ulceration. If gastric irritation occurs, it is recommended that Vidokcine Capsules be given with food or milk. Studies indicate that the absorption of Vidokcine is not notably influenced by simultaneous ingestion of food or milk.

Exceeding the recommended dosage may result in an increased incidence of side-effects.

Therapy should be continued for at least 24 to 48 hours after symptoms and fever have subsided. When used in streptococcal infections, therapy should be continued for 10 days to prevent the development of rheumatic fever or glomerulonephritis

The use of drugs of the tetracycline class during tooth development (pregnancy, infancy and childhood to the age of 12 years) may cause permanent discolouration of the teeth (yellow-grey-brown). This adverse reaction is more common during long-term use of the drugs but has been observed following repeated short-term courses. Enamel hypoplasia has also been reported. Vidokcine is therefore contraindicated in these groups of patients.

Pregnancy

Vidokcine is contra-indicated in pregnancy. It appears that the risks associated with the use of tetracyclines during pregnancy are predominantly due to effects on teeth and skeletal development. (See above about use during tooth development).

Nursing mothers

Tetracyclines are excreted into milk and are therefore contraindicated in nursing mothers. (See above about use during tooth development).

Paediatric population

Vidokcine is contraindicated in children under the age of 12 years. As with other tetracyclines, Vidokcine forms a stable calcium complex in any bone-forming tissue. A decrease in the fibula growth rate has been observed in prematures given oral tetracyclines in doses of 25 mg/kg every 6 hours. This reaction was shown to be reversible when the drug was discontinued. (See above about use during tooth development).

Use in patients with impaired hepatic function

Vidokcine should be administered with caution in patients with hepatic impairment or those receiving potentially hepatotoxic drugs. Abnormal hepatic function has been reported rarely and has been caused by both oral and parenteral administration of tetracyclines including Vidokcine.

Use in patients with renal impairment

Excretion of Vidokcine by the kidney is about 40%/72 hours in patients with normal renal function. This percentage excretion may fall to a range as low as 1-5%/72 hours in individuals with severe renal insufficiency (creatinine clearance below 10ml/min). Studies have shown no significant difference in the serum half-life of Vidokcine in individuals with normal and severely impaired renal function. Haemodialysis does not alter the serum half-life of Vidokcine. The anti-anabolic action of the tetracyclines may cause an increase in blood urea. Studies to date indicate that this anti-anabolic effect does not occur with the use of Vidokcine in patients with impaired renal function.

Photosensitivity

Photosensitivity manifested by exaggerated sunburn reaction has been observed in some individuals taking tetracyclines, including Vidokcine. Patients likely to be exposed to direct sunlight or ultraviolet light should be advised that this reaction can occur with tetracycline drugs and treatment should be discontinued at the first sign of skin erythema.

Benign intracranial hypertension

Bulging fontanelles in infants have been reported in individuals receiving tetracyclines. Benign intracranial hypertension (pseudotumor cerebri) has been associated with the use of tetracyclines including Vidokcine. Benign intracranial hypertension (pseudotumor cerebri) is usually transient, however cases of permanent visual loss secondary to benign intracranial hypertension (pseudotumor cerebri) have been reported with tetracyclines including Vidokcine. If visual disturbances occur during treatment, prompt ophthalmologic evaluation is warranted. Since intracranial pressure can remain elevated for weeks after drug cessation patients should be monitored until they stabilize. Concomitant use of isotretinoin or other systemic retinoids and Vidokcine should be avoided because isotretinoin is also known to cause benign intracranial hypertension (pseudotumor cerebri)..

Microbial overgrowth

The use of antibiotics may occasionally result in over-growth of non-susceptible organisms including Candida. If a resistant organism appears, the antibiotic should be discontinued and appropriate therapy instituted.

Pseudomembranous colitis has been reported with nearly all antibacterial agents, including Vidokcine, and has ranged in severity from mild to life-threatening. It is important to consider this diagnosis in patients who present with diarrhoea subsequent to the administration of the antibacterial agents.

Clostridium difficile

Associated diarrhoea (CDAD) has been reported with use of nearly all antibacterial agents, including Vidokcine, and may range in severity from mild diarrhoea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile.

C. difficile produces toxins A and B which contribute to the development of CDAD.

Hypertoxin-producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhoea following antibiotic use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents.

Oesophagitis

Instances of oesophagitis and oesophageal ulcerations have been reported in patients receiving the capsule and tablet form of the drugs in the tetracycline class, including Vidokcine. Most of the patients took medications immediately before going to bed or with inadequate amounts of fluid.

Porphyria

There have been rare reports of porphyria in patients receiving tetracyclines.

Venereal disease

When treating venereal disease when co-existent syphilis is suspected, proper diagnostic procedures, including dark-field examinations, should be utilised. In all such cases, monthly serological tests should be made for at least four months.

Beta-haemolytic streptococci infections

Infections due to group A beta-haemolytic streptococci should be treated for at least ten days.

Myasthenia gravis

Due to potential for weak neuromuscular blockade, care should be taken in administering tetracyclines to patients with Myasthenia gravis.

Systemic lupus erythematosus

Tetracyclines can cause the exacerbation of SLE.

Methoxyflurane

Caution is advised in administering tetracyclines with methoxyflurane.

The effect of Vidokcine on the ability to drive or operate heavy machinery has not been studied. There is no evidence to suggest that Vidokcine may affect these abilities.

The following adverse reactions have been observed in patients receiving tetracyclines, including Vidokcine.

Adverse Reactions Table

* Symptoms included blurring of vision, scotomata and diplopia. Permanent visual loss has been reported.

Tetracyclines may cause discolouration of teeth and enamel hypoplasia, but usually only after long-term use.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at www.mhra.gov.uk/yellowcard.

Acute overdosage with antibiotics is rare. In the event of overdosage discontinue medication. Gastric lavage plus appropriate supportive treatment is indicated.

Dialysis does not alter serum half-life and thus would not be of benefit in treating cases of overdosage.

Pharmacotherapeutic group: Tetracyclines, ATC code: J01 AA02

Vidokcine is primarily bacteriostatic and is believed to exert its antimicrobial effect by the inhibition of protein synthesis. Vidokcine is active against a wide range of Gram-positive and Gram-negative bacteria and certain other micro-organisms.

Absorption

Tetracyclines are readily absorbed and are bound to proteins in varying degrees. They are concentrated by the liver in the bile and excreted in the urine and faeces at high concentration and in a biologically active form. Vidokcine is virtually completely absorbed after oral administration. Studies reported to date indicate that the absorption of Vidokcine unlike certain other tetracyclines, is not notably influenced by the ingestion of food or milk.

Following a 200mg dose, normal adult volunteers averaged peak serum levels of 2.6 micrograms/ml at 2hours decreasing to 1.45micrograms/ml at 24 hours. Vidokcine has a high degree of lipid solubility and a low affinity for calcium. It is highly stable in normal human serum. Vidokcine will not degrade into an epianhydro form.

Not applicable.

None known

No special requirements.