E-DRUG: Dipyrone in Sweden (contd.)
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I will not elaborate on the reasons why dipyrone (also called
metamizole) was re-introduced in Sweden. I think enough has been
said by others. I will only say that I wish we had kept our need
clause because I fear this drug may also appear on the Norwegian
market again!.
[About the need clause: Since 1928 and until approx. 1992, the
requirements for quality, safety, efficacy, cost and need formed
the basis for drug evaluation in Norway. A drug could thus be denied
registration if the Committee found it of no additional therapeutic
value compared to therapeutically equivalent drug already on the
market or that it found the number of different generics to be high
enough to ensure competition. By including the need clause into the
Norwegian drug legislation, a social dimension was introduced into
drug policies at a very early stage. Drugs were not only assessed
purely from a scientific or technical point of view, but in the
light of health priorities and the delivery of health care to the
population as a whole. When adopting the EU legislation and
regulation, we had to abolish the clause, allowing the market to be
flooded with new, expensive drugs of no additional benefit.
The 'Obituary' can be found in HAI NEWS No.64, April 1992 page 5. To
obtain HAI NEWS please email: ciroap@pc.jaring.my]
I am reproducing below excerpts on dipyrone from the information in
the Swedish FASS (physicians' desk reference):
Dosage forms: tablets and injection
Indications:
Short-term treatment of acute moderate to serious pain in
connection with tissue damage, e.g. surgical procedures, and colic
pain, e.g. in urinary or gallbladder tracts.
Control of treatment:
If symptoms of agranulocytosis or thrombocytopaenia occur, stop
treatment immediately and do a blood count (incl. counting of
white blood cells).
The patient should be told to discontinue treatment if any of the
mentioned adverse effects or other unwanted effects occur, and
contact a physician.
Contraindications:
Hypersensitivity to metamizole and other pyrazolone derivatives
(e.g. phenazonum) or pyrazolidines. Hepatic porphyria. Congenital
G6PD deficiency (risk of haemolysis).
Warnings and cautions:
Reduced liver- and kidney function. Because of possible cross
reaction and hence risk of serious anaphylactic reactions, the
drug should not be given to patients with symptoms of asthma,
rhinitis, or urticaria when taking ASA (acetyl salicylic acid or
aspirin), other NSAIDs (Nonsteroidal anti-inflammatory drugs) or
other pain killers (e.g. paracetamol).
Metamizole may cause isolated hypotensive reactions which one
should be particularly alerted to when treating patients which
manifest hypotension, fluid loss, circulatory instability, initial
signs of circulatory collapse. Lack of experience in longterm
treatment.
Interactions:
Metamizole may decrease serum levels of cyclosporine.
Documentation available indicates that cytochrome P450 is involved
in the metabolism of metamizole. Studies to characterize the
isoenzymes responsible for the metabolism is lacking, and potential
interactions may thus not be predicted.
Studies of interactions with warfarin are lacking.
Simultaneous intake of alcohol should be avoided.
Pregnancy:
Metamizole may inhibit contractions in uterus and prolong delivery.
It may even cause pulmonary hypertension and neonatal respiratory
insufficiency through contraction or closure of ductus arteriosus
intrauterinally. Thrombocytic function in the foetus may be
inhibited. Effects described in the foetus is thought to be caused
by inhibition of prostaglandin synthesis.
During last trimester, treatment with antiflogistics which inhibit
prostaglandin synthesis should only be prescribed after careful
consideration. During the period immediately before delivery, such
drugs should not be used.
Breast milk:
Metamizole is found in such concentration in breast milk that even
therapeutic doses may influence the baby. 48 hours after last dose,
no metabolites can be detected in the breast milk.
Adverse effects:
1/100-1/1000:
Hypotensive reactions less than 1/1000: Anaphylactic/anaphylactoid
reactions. Leucopaenia, agranulocytosis (1:1 mill),
thrombocytopaenia, maculopapular rash, acute kidney failure,
sometimes with anuria and oliguria, interstitial nephritis.
Pain and local reactions, e.g. thrombophlebitis, at injection site
may occur. Steven Johnson's or Lyell's syndrome has been reported.
Mild to serious anaphylactic/anaphylactoid reactions may occur in
connection with administration. Usually they occur within 1 hour.
Serious hypotensive reactions occur rarely.
Preventive measures (stabilisation of circulation) may become
necessary to reduce the risk of such reactions.
Typical signs of agranulocytosis include inflammatory mucous
lesions (e.g. oropharyngeal, anorectal, genital), sore throat and
fever. Symptoms may be less prominent in patients taking
antibiotics simultaneously.
Regards
Ms Kirsten Myhr, MScPharm, MPH
Bygdoy Alle 58B
0265 Oslo
Norway
Tel: +47 22 56 05 85 (h)
Fax: +47 22 24 90 17 (w) Tel: +47 22 24 90 04 (w)
E-mail: myhr@online.no
or (w): kirsten.myhr@helsetilsynet.dep.telemax.no
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