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Stemetil 12.5mg/ml Injection


Each 1 ml of Stemetil injection contains 12.5 mg prochlorperazine mesilate.
Each 1 ml of Stemetil injection contains 1 mg of sodium sulphite, 0.75 mg of
sodium metabisulphite and 6 mg of sodium chloride.
For a full list of excipients, see section 6.1.


Colourless sterile solution.




Therapeutic indications
Stemetil is a potent phenothiazine neuroleptic.
Uses: The treatment of nausea and vomiting and in schizophrenia (particularly
the chronic stage) and acute mania.


Posology and method of administration
For deep intramuscular injection.


Treatment of nausea and vomiting

12.5 mg by deep i.m. injection followed by oral
medication 6 hours later if necessary.

Reference: 32895 - name - SPC 1 - 12.5mg/ml - 2009-02-05 1.4

Schizophrenia and other psychotic

12.5 mg to 25 mg b.i.d. or t.d.s. by deep i.m.
injection until oral treatment becomes possible.

Intramuscular Stemetil should not be given to children.
A lower dose is recommended (see section 4.4).


Known hypersensitivity to prochlorperazine or to any of the other ingredients.
The use of Stemetil injection is contraindicated in children as it has been
associated with dystonic reactions after the cumulative dose of 0.5 mg/kg.


Special warnings and precautions for use
Stemetil should be avoided in patients with liver or renal dysfunction, Parkinson’s
disease, hypothyroidism, cardiac failure, phaeochromocytoma, myasthenia gravis,
prostate hypertrophy. It should be avoided in patients known to be hypersensitive to
phenothiazines or with a history of narrow angle glaucoma or agranulocytosis.
Close monitoring is required in patients with epilepsy or a history of seizures, as
phenothiazines may lower the seizure threshold.
As agranulocytosis has been reported, regular monitoring of the complete blood count
is recommended. The occurrence of unexplained infections or fever may be evidence
of blood dyscrasia (see section 4.8), and requires immediate haematological
It is imperative that treatment be discontinued in the event of unexplained fever, as
this may be a sign of neuroleptic malignant syndrome (pallor, hyperthermia,
autonomic dysfunction, altered consciousness, muscle rigidity). Signs of autonomic
dysfunction, such as sweating and arterial instability, may precede the onset of
hyperthermia and serve as early warning signs. Although neuroleptic malignant
syndrome may be idiosyncratic in origin, dehydration and organic brain disease are
predisposing factors.
Acute withdrawal symptoms, including nausea, vomiting and insomnia, have very
rarely been reported following the abrupt cessation of high doses of neuroleptics.
Relapse may also occur, and the emergence of extrapyramidal reactions has been
reported. Therefore, gradual withdrawal is advisable.
In schizophrenia, the response to neuroleptic treatment may be delayed. If treatment
is withdrawn, the recurrence of symptoms may not become apparent for some time.

Reference: 32895 - name - SPC 1 - 12.5mg/ml - 2009-02-05 1.4

Neuroleptic phenothiazines may potentiate QT interval prolongation which increases
the risk of onset of serious ventricular arrhythmias of the torsade de pointes type,
which is potentially fatal (sudden death). QT prolongation is exacerbated, in
particular, in the presence of bradycardia, hypokalaemia, and congenital or acquired
(i.e. drug induced) QT prolongation. The risk-benefit should be fully assessed before
Stemetil treatment is commenced. If the clinical situation permits, medical and
laboratory evaluations (e.g. biochemical status and ECG) should be performed to rule
out possible risk factors (e.g. cardiac disease; family history of QT prolongation;
metabolic abnormalities such as hypokalaemia, hypocalcaemia or hypomagnesaemia;
starvation; alcohol abuse; concomitant therapy with other drugs known to prolong the
QT interval) before initiating treatment with Stemetil and during the initial phase of
treatment, or as deemed necessary during the treatment (see sections 4.5 and 4.8).
Avoid concomitant treatment with other neuroleptics (see section 4.5).
In randomised clinical trials versus placebo performed in a population with elderly
patients with dementia and treated with certain atypical antipsychotic drugs, a 3-fold
increase of the risk of cerebrovascular events has been observed. The mechanism of
such risk increase is not known. An increase in the risk with other antipsychotic drugs
or other populations of patients cannot be excluded. Stemetil should be used with
caution with stroke risk factors.
As with all antipsychotic drugs, Stemetil should not be used alone where depression
is predominant. However, it may be combined with antidepressant therapy to treat
those conditions in which depression and psychosis coexist.
Because of the risk of photosensitisation, patients should be advised to avoid
exposure to direct sunlight.
To prevent skin sensitisation in those frequently handling preparations of
phenothiazines, the greatest care must be taken to avoid contact of the drug with the
skin (see section 4.8).
Postural hypotension with tachycardia as well as local pain or nodule formation may
occur after i.m. administration.
It should be used with caution in the elderly, particularly during very hot or very cold
weather (risk of hyper-, hypothermia).
The elderly are particularly susceptible to postural hypotension.
Stemetil should be used cautiously in the elderly owing to their susceptibility to drugs
acting on the central nervous system and a lower initial dosage is recommended.
There is an increased risk of drug-induced Parkinsonism in the elderly particularly
after prolonged use. Care should also be taken not to confuse the adverse effects of
Stemetil, e.g. orthostatic hypotension, with the effects due to the underlying disorder.
Increased Mortality in Elderly people with Dementia
Data from two large observational studies showed that elderly people with dementia
who are treated with antipsychotics are at a small increased risk of death compared
with those who are not treated. There are insufficient data to give a firm estimate of
the precise magnitude of the risk and the cause of the increased risk is not known.
Stemetil is not licensed for the treatment of dementia-related behavioural

Reference: 32895 - name - SPC 1 - 12.5mg/ml - 2009-02-05 1.4

Cases of venous thromboembolism (VTE) have been reported with antipsychotic
drugs. Since patients treated with antipsychotics often present with acquired risk
factors for VTE, all possible risk factors for VTE should be identified before and
during treatment with Stemetil and preventative measures undertaken.
Hyperglycaemia or intolerance to glucose had been reported in patients treated with
antipsychotic phenothiazines. Patients with an established diagnosis of diabetes
mellitus or with risk factors for the development of diabetes, who are started on
Stemetil, should get appropriate glycaemic monitoring during treatment (see section


Interaction with other medicinal products and other forms of interaction
Adrenaline must not be used in patients overdosed with Stemetil (see section 4.9).
The CNS depressant actions of neuroleptic agents may be intensified (additively) by
alcohol, barbiturates and other sedatives. Respiratory depression may occur.
Anticholinergic agents may reduce the antipsychotic effect of neuroleptics and the
mild anticholinergic effect of neuroleptics may be enhanced by other anticholinergic
drugs, possibly leading to constipation, heat stroke, etc.
Some drugs interfere with absorption of neuroleptic agents: antacids, anti-Parkinson
drugs and lithium.
Where treatment for neuroleptic-induced extrapyramidal symptoms is required,
anticholinergic antiparkinsonian agents should be used in preference to levodopa,
since neuroleptics antagonise the antiparkinsonian action of dopaminergics.
High doses of neuroleptics reduce the response to hypoglycaemic agents, the dosage
of which might have to be raised.
The hypotensive effect of most antihypertensive drugs especially alpha adrenoceptor
blocking agents may be exaggerated by neuroleptics.
The action of some drugs may be opposed by phenothiazine neuroleptics; these
include amfetamine, levodopa, clonidine, guanethidine, adrenaline.
Increases or decreases in the plasma concentrations of a number of drugs, e.g.
propranolol, phenobarbital have been observed but were not of clinical significance.
Simultaneous administration of desferrioxamine and prochlorperazine has been
observed to induce transient metabolic encephalopathy characterised by loss of
consciousness for 48-72 hours.
There is an increased risk of arrhythmias when antipsychotics are used with
concomitant QT prolonging drugs (including certain antiarrhythmics, antidepressants
and other antipsychotics) and drugs causing electrolyte imbalance.
There is an increased risk of agranulocytosis when neuroleptics are used concurrently
with drugs with myelosuppressive potential, such as carbamazepine or certain
antibiotics and cytotoxics.

Reference: 32895 - name - SPC 1 - 12.5mg/ml - 2009-02-05 1.4

In patients treated concurrently with neuroleptics and lithium, there have been rare
reports of neurotoxicity.


Pregnancy and lactation
There is inadequate evidence of safety in pregnancy. There is evidence of harmful
effects in animals. Stemetil should be avoided in pregnancy unless the physician
considers it essential. Neuroleptics may occasionally prolong labour and at such time
should be withheld until the cervix is dilated 3-4 cm. Possible adverse effects on the
neonate include lethargy or paradoxical hyperexcitability, tremor and low apgar score.
Neonates exposed to antipsychotics (including Stemetil) during the third trimester of
pregnancy are at risk of adverse reactions including extrapyramidal and/or withdrawal
symptoms that may vary in severity and duration following delivery. There have been
reports of agitation, hypertonia, hypotonia, tremor, somnolence, respiratory distress,
or feeding disorder. Consequently, newborns should be monitored carefully.
Phenothiazines may be excreted in milk; therefore breast feeding should be suspended
during treatment.


Effects on ability to drive and use machines
Patients should be warned about drowsiness during the early days of treatment
and advised not to drive or operate machinery.


Undesirable effects
Generally, adverse reactions occur at a low frequency; the most common
reported adverse reactions are nervous system disorders.
Adverse effects:
Immune System Disorders:
Type I hypersensitivity reactions such as angioedema and urticaria.
Blood and lymphatic system disorders: A mild leukopenia occurs in up to
30% of patients on prolonged high dosage. Agranulocytosis may occur rarely:
it is not dose related (see section 4.4).
Endocrine: Hyperprolactinaemia which may result in galactorrhoea,
gynaecomastia, amenorrhoea, impotence.
Nervous system disorders: Acute dystonia or dyskinesias, including
oculogyric crisis, usually transitory are commoner in children and young

Reference: 32895 - name - SPC 1 - 12.5mg/ml - 2009-02-05 1.4

adults, and usually occur within the first 4 days of treatment or after dosage
Akathisia characteristically occurs after large initial doses.
Parkinsonism is more common in adults and the elderly. It usually develops
after weeks or months of treatment. One or more of the following may be
seen: tremor, rigidity, akinesia or other features of Parkinsonism. Commonly
just tremor.
Tardive dyskinesia: If this occurs it is usually, but not necessarily, after
prolonged or high dosage. It can even occur after treatment has been stopped.
Dosage should therefore be kept low whenever possible.
Insomnia and agitation may occur.
Eye disorders: Ocular changes and the development of metallic greyishmauve coloration of exposed skin have been noted in some individuals mainly
females, who have received chlorpromazine continuously for long periods
(four to eight years). This could possibly happen with Stemetil.
Cardiac disorders: ECG changes include QT prolongation (as with other
neuroleptics), ST depression, U-Wave and T-Wave changes. Cardiac
arrhythmias, including ventricular arrhythmias and atrial arrhythmias, a-v
block, ventricular tachycardia, which may result in ventricular fibrillation or
cardiac arrest have been reported during neuroleptic phenothiazine therapy,
possibly related to dosage. Pre-existing cardiac disease, old age, hypokalaemia
and concurrent tricyclic antidepressants may predispose.
There have been isolated reports of sudden death, with possible causes of
cardiac origin (see section 4.4), as well as cases of unexplained sudden death,
in patients receiving neuroleptic phenothiazines.
Vascular disorders: Hypotension, usually postural, commonly occurs. Elderly
or volume depleted subjects are particularly susceptible; it is more likely to
occur after intramuscular injection. Cases of venous thromboembolism,
including cases of pulmonary embolism and cases of deep vein thrombosis
have been reported with antipsychotic drugs – Frequency unknown.
Gastrointestinal disorders: dry mouth may occur.
Metabolism and nutrition disorders:
Hyponatraemia, syndrome of inappropriate antidiuretic hormone secretion.
Respiratory, thoracic and mediastinal disorders: Respiratory depression is
possible in susceptible patients. Nasal stuffiness may occur.

Reference: 32895 - name - SPC 1 - 12.5mg/ml - 2009-02-05 1.4

Hepato-biliary disorders: Jaundice, usually transient, occurs in a very small
percentage of patients taking neuroleptics. A premonitory sign may be sudden
onset of fever after one to three weeks of treatment followed by the
development of jaundice. Neuroleptic jaundice has the biochemical and other
characteristics of obstructive jaundice and is associated with obstruction of the
canaliculi by bile thrombi; the frequent presence of an accompanying
eosinphilia indicates the allergic nature of this phenomenon. Treatment should
be withheld on the development of jaundice (see section 4.4).
Skin and subcutaneous tissue disorders: Contact skin sensitisation may occur
rarely in those frequently handling preparations of certain phenothiazines (see
section 4.4). Skin rashes of various kinds may also be seen in patients treated
with the drug. Patients on high dosage should be warned that they may
develop photosensitivity in sunny weather and should avoid exposure to direct
General disorders and administration site conditions: Neuroleptic malignant
syndrome (hyperthermia, rigidity, autonomic dysfunction and altered
consciousness) may occur with any neuroleptic (see section 4.4).
Intolerance to glucose, hyperglycaemia (see section 4.4).
Pregnancy, puerperium and perinatal conditions; drug withdrawal syndrome
neonatal (see section 4.6) – Frequency not known.
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 Yellow Card Scheme at:


Symptoms of phenothiazine overdosage include drowsiness or loss of
consciousness, hypotension, tachycardia, ECG changes, ventricular
arrhythmias and hypothermia. Severe extrapyramidal dyskinesias may occur.
If the patient is seen sufficiently soon (up to 6 hours) after ingestion of a toxic
dose, gastric lavage may be attempted. Pharmacological induction of emesis
is unlikely to be of any use. Activated charcoal should be given. There is no
specific antidote. Treatment is supportive.
Generalised vasodilatation may result in circulatory collapse; raising the
patient’s legs may suffice. In severe cases, volume expansion by intravenous
fluids may be needed; infusion fluids should be warmed before administration
in order not to aggravate hypothermia.

Reference: 32895 - name - SPC 1 - 12.5mg/ml - 2009-02-05 1.4

Positive inotropic agents such as dopamine may be tried if fluid replacement is
insufficient to correct the circulatory collapse. Peripheral vasoconstrictor
agents are not generally recommended. Avoid the use of adrenaline.
Ventricular or supraventricular tachy-arrhythmias usually respond to
restoration of normal body temperature and correction of circulatory or
metabolic disturbances. If persistent or life threatening, appropriate antiarrhythmic therapy may be considered. Avoid lidocaine and, as far as
possible, long acting anti-arrhythmic drugs.
Pronounced central nervous system depression requires airway maintenance
or, in extreme circumstances, assisted respiration. Severe dystonic reactions
usually respond to procyclidine (5-10 mg) or orphenadrine (20-40 mg)
administered intramuscularly or intravenously. Convulsions should be treated
with intravenous diazepam.
Neuroleptic malignant syndrome should be treated with cooling. Dantrolene
sodium may be tried.




Pharmacodynamic properties
Pharmacotherapeutic group: Psycholeptics; Phenothiazines with piperazine structure,
ATC code: N05AB04
Stemetil is a potent phenothiazine neuroleptic.


Pharmacokinetic properties
There is little information about blood levels, distribution and excretion in
humans. The rate of metabolism and excretion of phenothiazines decreases in
old age.


Preclinical safety data
There are no preclinical data of relevance to the prescriber which are
additional to that already included in other sections of the SPC.

Reference: 32895 - name - SPC 1 - 12.5mg/ml - 2009-02-05 1.4




List of excipients
Sodium sulphite anhydrous (E221)
Sodium metabisulphite powder (E223)
Sodium chloride
Water for injections (non-sterilised)


Not applicable


Shelf life
5 years


Special precautions for storage
Keep ampoules in the outer carton, in order to protect from light. Discoloured
solutions should not be used.


Nature and contents of container
Stemetil injection is supplied in colourless glass ampoules in packs of 10 x
1ml and 10 x 2ml.
Not all pack sizes may be marketed.


Special precautions for disposal

No special requirements

Reference: 32895 - name - SPC 1 - 12.5mg/ml - 2009-02-05 1.4


Aventis Pharma Limited also trading as
Aventis Pharma
One Onslow Street
Or trading as
Sanofi-aventis or Sanofi
One Onslow Street


PL 04425/0590


Date of first authorisation: 28 February 1973
Date of latest renewal: 16 September 2002



Reference: 32895 - name - SPC 1 - 12.5mg/ml - 2009-02-05 1.4

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Source: Medicines and Healthcare Products Regulatory Agency

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