Anapen

How does it work?

• EpiPen and EpiPen Jr auto-injectors both contain the active ingredient adrenaline, which is a hormone produced naturally by the body.
• Adrenaline is usually released by the adrenal glands in times of stress. It prepares the body when extra energy or exertion is needed, making the body more able to deal with life-threatening situations.
• Adrenaline (sometimes called epinephrine) is given by injection to treat a life-threatening allergic reaction called anaphylactic shock.
• Anaphylatic shock is a severe, potentially life-threatening allergic reaction that can be triggered in people with a severe allergy to a drug, food or other allergen, or to an insect bite or sting. A severe reaction of this type can happen within minutes of being exposed to the thing you are allergic to and can include the following symptoms: a feeling of apprehension, swelling of the lips, tongue and throat, wheezing, difficulty breathing or swallowing, fall in blood pressure causing dizziness or faintness, feeling sick, vomiting, flushing, fast heartbeat, weak pulse, tightening of the chest, itching of the skin, a raised rash (like a nettle rash), and in some cases loss of consciousness or convulsions.
• An injection of adrenaline rapidly reverses the symptoms of anaphylaxis by acting on alpha and beta adrenergic receptors in the body.
• The alpha receptors are found on the walls of blood vessels. When adrenaline stimulates these receptors this causes the blood vessels to narrow, which stops the blood pressure from falling too low. It also redirects blood to vital organs like the heart and brain.
• The beta receptors are found in the heart and lungs. When adrenaline stimulates these receptors this relaxes and opens the airways, making breathing easier. It also stimulates the heart, making it beat faster and stronger.
• Adrenaline also relieves itching, hives and swelling.

How do I use it?

• The EpiPen is designed to be used by people with no medical training at the first signs of an anaphylactic reaction. Your doctor will teach you how and when to use it.
• It is very important to use the EpiPen only as instructed by your doctor. You should make sure that you understand exactly WHEN and HOW to use the EpiPen. If you are at all unclear about when or how to use the injection you should ask your doctor or pharmacist to explain the instructions again so that you know what to do in an emergency.
• The EpiPen can be injected through clothes if necessary.
• Pull off the blue cap, then jab the orange tip of the EpiPen firmly into the outer thigh at a right angle, from a distance of approximately 10cm. This releases a spring-activated plunger that pushes the hidden needle into the thigh muscle and delivers a dose of adrenaline. You should hear a click. The pen should be held firmly in the thigh for 10 seconds and then removed.
• Massage the area where you have adminstered the injection for ten seconds to improve the absorption of the adrenaline.
• EpiPen auto-injectors should ONLY be injected into the outer side of the thigh. Do NOT inject into a vein, or into the buttock, as this may accidentally inject into a vein.
• An ambulance should be called after every time you need to use the EpiPen, even if symptoms are improving. Dial 999, ask for an ambulance and state 'anaphylaxis'. The person who has been treated with the EpiPen should lie down with legs their raised and, if at all possible, should not be left alone.
• If the symptoms of the allergic reaction do not improve or get worse a second EpiPen should be used 5 to 15 minutes after the first.

Warning!

• This medicine must only be used to treat anaphylaxis in people who have been prescribed the EpiPen by their doctor. This will be because they have a history or recognised risk of going into anaphylactic shock. The EpiPen should not be used to treat anyone else, even if they have similar symptoms.
• If the Epipen auto-injector is accidentally injected into the hands, fingers or feet it may result in loss of blood flow to this area. If you do accidentally inject it into one of these areas then emergency medical treatment should be sought immediately. Never put your thumb, fingers or hand over the orange tip of the EpiPen and do not remove the blue safety cap until you are ready to use the EpiPen.
• Always keep the EpiPen in its outer container to protect it from light. When exposed to air or light, adrenaline deteriorates rapidly and will become pink or brown. The pens should be stored below 25°C. Do not keep them in a fridge or allow them to freeze.
• You should check the expiry date on your EpiPens regularly. Also check the contents of the glass cartridge in your EpiPens from time to time to make sure that the solution is clear and colourless. If the solution is discoloured or contains particles, or the pen has expired, you should consult your doctor for a new prescription and return the EpiPen to your pharmacist.

Not to be used in

• There are no known conditions in which EpiPen should not be used to treat an allergic emergency.
• The injection should be administered into the outer thigh only. Make sure you don't accidentally inject it into the buttock, or into the hands or fingers (see warnings above).

Use with caution in

Adrenaline is essential for the treatment of anaphylaxis. However, the following people may be at increased risk of side effects after using EpiPen.

• People with heart disease or an irregular heartbeat (arrhythmias).
• People with high blood pressure (hypertension).
• People with an overactive thyroid gland (hyperthyroidism).
• People with a tumour of the adrenal gland (phaeochromocytoma).
• People with diabetes.
• People with raised pressure in the eyeball, eg glaucoma.
• People with a high level of calcium or low level of potassium in their blood.
• People with an allergy to sodium metabisulphite, which is used as a preservative in this product.
• Elderly people.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

• It is very important that you fully understand in which situations to use this medicine if you are pregnant. It should only be used if the benefits outweigh any risks to the baby. However, in an emergency you should not hesitate to use this medicine, since anaphylaxis can be life-threatening for you and your baby. Seek further medical advice from your doctor.
• In an emergency you should not hesitate to use this medicine if you are breastfeeding, since anaphylaxis can be life-threatening. Any adrenaline that passes into breast milk is not expected to have any effect on a nursing infant, because adrenaline is not absorbed when taken by mouth. Seek further medical advice from your doctor.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect.

• Headache.
• Nausea and vomiting.
• Feeling weak.
• Dizziness.
• Paleness.
• Sweating.
• Anxiety and nervousness.
• Shaking, usually of the hands (tremor).
• Awareness of your heartbeat (palpitations).
• Faster than normal heart beat (tachycardia).
• Abnormal heart beats (arrhythmias).
• Difficulties with breathing.

The side effects listed above may not include all of the side effects reported by the medicine's manufacturer. For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking when you are prescribed this medicine, including those bought without a prescription and herbal medicines, so they can check that the combination is safe.

There may be an increased risk of side effects on the heart if this injection is used by people taking any of the following medicines:

• beta-blockers eg propranolol
• digoxin
• entacapone
• MAOI antidepressants, eg phenelzine, isocarboxazid, tranylcypromine, moclobemide
• quinidine
• rasagiline
• selegiline
• tricyclic antidepressants, eg amitriptyline.

Adrenaline can decrease the amount of insulin produced by the body; this can cause an increase in blood sugar levels. People with diabetes should therefore carefully monitor their blood sugar after using this medicine.

References:

http://www.netdoctor.co.uk/medicines/allergy-and-asthma/a6668/epipen-adrenaline/

http://www.anapen.ie