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Pentazocine 25 mg
Film-coated Tablets
(Pentazocine hydrochloride)

Read all of this leaflet carefully before
you start taking this medicine because it
contains important information for you.
• Keep this leaflet. You may need to read it
• If you have any further questions, ask your
doctor or pharmacist.
• This medicine has been prescribed for you
only. Do not pass it on to others. It may
harm them, even if their signs of illness are
the same as yours.
• If you get any side effects talk to your
doctor or pharmacist. This includes any
possible side effects not listed in this
leaflet. See section 4.
What is in this leaflet:
1. What Pentazocine is and what it is used for
2. What you need to know before you take
3. How to take Pentazocine
4. Possible side effects
5. How to store Pentazocine
6. Contents of the pack and other information
1. What Pentazocine is and what it is
used for

2. What you need to know before you
take Pentazocine
Do not take Pentazocine if you:
• Are allergic to pentazocine, or any of the
other ingredients of this medicine (listed in
section 6).
• Have breathing problems for example,
respiratory depression and /or shallow
breathing (which may lead to blue lips),
chronic bronchitis (coughing up a lot of
phlegm) or asthma
• Have a history of alcohol abuse
• Are recovering from a head injury, or you
have a condition which causes increased
pressure on the brain. Symptoms include
severe headaches, being sick, drowsiness or
blurred vision
• Have heart failure or suffer from
breathlessness and swollen ankles
• Have porphyria (a genetic disease that can
cause skin blisters, abdominal pain and brain
or nervous system disorders).


Warnings and precautions
Talk to your doctor or pharmacist before
taking Pentazocine if you:
• Are taking a monoamine oxidase inhibitor
(MAOI, a medicine used for depression e.g.
phenelzine, isocarboxazid) or you have taken
one within the last 14 days
• Have a rare tumour of the adrenal glands
called a phaeochromocytoma. This may
cause headaches, sweating, palpitations,
flushing of the face and pains in the chest or
• Have recently had a heart attack
• Have high blood pressure
• Have severe kidney or liver disease, or you
are elderly. You may need a lower dose
• Have epilepsy
• Have a history of drug abuse, or you are
addicted to opiate pain killers such as
morphine or diamorphine
• Are being treated for an underactive thyroid
• Have a condition which affects your adrenal
• Have an enlarged prostate gland and have
difficulty urinating
• Suffer from an inflamed bowel or other gut
• Are a smoker, the effect of Pentazocine may
be decreased
• Have been regularly taking other pain
relieving medicines for longer than three
months, especially if you are suffering from
headaches or headaches have become

Pentazocine with alcohol
Do not drink alcohol whilst taking this
Pregnancy and breast-feeding
If you are pregnant, or breast-feeding, think
you may be pregnant, or are planning to have
a baby, ask your doctor or pharmacist for
advice before taking this medicine.
Driving and using machines
Pentazocine may cause sedation. If affected
you should not drive or use machines.
The medicine can affect your ability to drive as
it may make you sleepy or dizzy.
• Do not drive while taking this medicine until
you know how it affects you.
• It is an offence to drive if this medicine
affects your ability to drive.
• However, you would not be committing an
offence if:
• The medicine has been prescribed to treat
a medical or dental problem and
• You have taken it according to the
instructions given by the prescriber or
in the information provided with the
medicine and
• It was not affecting your ability to drive
Talk to your doctor or pharmacist if you are
not sure whether it is safe for you to drive
while taking this medicine.
Pentazocine contains sodium
metabisulfite which may rarely cause severe
hypersensitivity reactions and bronchospasm.
3. How to take Pentazocine
Always take this medicine exactly as your
doctor or pharmacist has told you. Check with
your doctor or pharmacist if you are not sure.
Swallow the tablets whole with a full glass of
water. The tablets should be taken after meals.
Do not chew or crush the tablets.
Your doctor will decide how much
Pentazocine you should take. This will depend
on your condition and the severity of your
The recommended dose is:
Adults - Two 25 mg tablets every four hours,
after meals. If more pain relief is needed
your doctor may increase your dose up to a
maximum of four tablets every three to four
hours after meals.
Use in children and adolescents - Children
between the ages of 6 and 12 years old will
usually be given one 25 mg tablet every 3 to 4
hours. This medicine is not recommended for
children under 6 years old.
Older people or patients with kidney or liver
Your doctor may give you a lower dose.
If you take more Pentazocine than you
Contact your doctor or nearest hospital
emergency department immediately. Take
the container and any remaining tablets with
you. Signs of overdose include drowsiness,
shallow breathing, low blood pressure, fast
heartbeat, hallucinations (seeing things that
are not there) coma or fits.
If you forget to take Pentazocine
Take the next dose at the usual time. Do not
take a double dose to make up for a forgotten



Pentazocine belongs to a group of medicines
called opioid analgesics. These are strong pain
killers that are used to relieve moderate to
severe pain.

Other medicines and Pentazocine
Tell your doctor or pharmacist if you are
taking, have recently taken or might take
any other medicines, especially any of the
• Other strong pain killers (e.g. morphine,
diamorphine, naloxone)
• Phenothiazines (used to treat mental
disorders, e.g. chlorpromazine, thioridazine)
• Monoamine oxidase inhibitors (see Warnings
and precautions)
• Doxapram (used to stimulate breathing).


Package leaflet:
Information for the patient

If you stop taking Pentazocine
Do not take your tablets more often or for
longer than your doctor advises. Too much
Pentazocine can be habit forming. This is
called dependence. If you stop taking your
medicine suddenly it can cause withdrawal
effects such as sweating, fever, weakness and
muscular pains. Your doctor will help you stop
your tablets gradually to avoid you having
these withdrawal symptoms.
If you have any further questions on the use of
this medicine, ask your doctor or pharmacist.
4. Possible side effects
Like all medicines, this medicine can cause
side effects, although not everybody gets
them. If they occur, they are likely to be mild.
However, some may be serious and need
medical attention.
If the following side effects occur, stop
taking the tablets immediately and contact
your doctor:
• sore throat, fever, severe chills and
mouth ulcers. This can be due to a lack
of white blood cells called granulocytes
• swelling of the face, lips, tongue or throat,
difficulty in swallowing or breathing, skin
rash or itchy flushed face (allergic reaction)
• blood changes such as a reduction in white
blood cells which makes infection (with
signs such as fever) more likely.
• a serious skin reaction called toxic epidermal
necrolysis. This is rare; symptoms include
loss of the outer layers of skin and reddening
of the skin.
Other possible side effects are:
• light-headedness, dizziness
• feeling sick, vomiting, constipation
• feeling drowsy
• fainting
• sweating
• headache
• dry mouth
• pins and needles
• ureteric or biliary tract spasm causing
abdominal cramps
• urinary retention (difficulty passing water)
• itching or flushing of the skin
• rapid heartbeat or slower heartbeat
• palpitations
• increased pressure on the brain
• slow or shallow breathing
• collapse due to very low blood pressure
• short-lived hypertension (high blood pressure)
• altered contractions of the womb
• muscle tremor
• grand mal convulsions (seizures)
• mood changes, difficulties sleeping,
nightmares, thought disturbances,
disorientation, confusion, hallucinations
(sensing things that are not real e.g. seeing
• extremes of feeling happy or sad
• eyesight changes
• chills
• lack of sexual desire, and impotency (failure
to maintain an erection)
• hypothermia (low body temperature)

6. Contents of the pack and other
What Pentazocine Tablets contain
The active substance is pentazocine
hydrochloride. Each tablet contains 25 mg
pentazocine hydrochloride.
The other ingredients are microcrystalline
cellulose, pregelatinised maize starch, calcium
hydrogen phosphate, dihydrate sodium
metabisulfite, sodium lauril sulfate, colloidal
anhydrous silica, magnesium stearate,
croscarmellose sodium. The coating contains
hypromellose, titanium dioxide (E171),
polyethylene glycol, carnauba wax.
What Pentazocine Tablets look like and
contents of the pack
Your medicine comes as a white tablet
marked with “PT” and “25” on one side and “G”
on the reverse.
Pentazocine is available in containers or
blister packs of 5, 7, 10, 14, 15, 20, 21, 25, 28,
30, 56, 60, 84, 90, 100 112, 120, 168, 180, and
500 tablets
Not all pack sizes may be marketed.
Marketing Authorisation Holder
Potters Bar,
EN6 1TL,
United Kingdom.
Generics [UK] Limited,
Potters Bar,
EN6 1TL,
United Kingdom.
Gerard Laboratories,
35/36 Baldoyle Industrial Estate,
Grange Road,
Dublin 13,
This leaflet was last revised in: August 2014

Reporting of side effects
If you get any side effects, talk to your doctor
or pharmacist. This includes any possible side
effects not listed in this leaflet.
You can also report side effects
via the Yellow Card Scheme at
www. By reporting
side effects you can help provide more
information on the safety of this medicine.
5. How to store Pentazocine
Keep this medicine out of the sight and
reach of children.
Store below 25°C.
Blister packs: Store in the original package in
order to protect from light and moisture.
Bottle packs: Keep the bottle tightly closed in
order to protect from light and moisture.
Do not use pentazocine after the expiry date
which is stated on the container after ‘EXP’.
The expiry date refers to the last day of that
Do not throw away any medicines via
wastewater or household waste. Ask your
pharmacist how to throw away medicines
you no longer use. These measures will help
protect the environment.


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