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Atropen

atropine
Used for Chemical Poisoning
Used for Chemical Poisoning

AtroPen (atropine) is a prefilled injectable pen that's used to treat poisoning caused by organophosphorus or carbamate insecticides (used for pesticides) or other organophosphorus nerve agent. These highly toxic and poisonous chemicals can prevent the nervous system from working properly. AtroPen (atropine) is only used as the first step in emergency treatment and must be followed by medical help.

Reviewed by:
reviewer
Yen Nguyen, PharmD
reviewer
Kristianne Hannemann, PharmD
Last reviewed on October 20, 2022
BasicsSide effectsPros & consPharmacist tipsFAQsWarningsDosagePricesMedicare
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What is AtroPen (atropine)?

What is AtroPen (atropine) used for?

  • Organophosphorus nerve agent poisoning

  • Organophosphorus or carbamate insecticide poisoning

How AtroPen (atropine) works

AtroPen (atropine) is an anticholinergic medication. It blocks the effects of acetylcholine, a chemical that plays an important role in brain and muscle function.

During organophosphorus or carbamate poisoning, the body isn't able to break down acetylcholine as it should. This causes too much acetylcholine to build up in the body, which can lead to symptoms like excessive saliva and tears, diarrhea, nausea, vomiting, small pupils, sweating, muscle tremors, trouble breathing, and confusion.

By blocking acetylcholine effects around the body and in the central nervous system, AtroPen (atropine) works well to treat organophosphorus and carbamate poisoning.

Are you looking for information on atropine eye drops (Isopto Atropine) instead?

Drug Facts

Common BrandsAtroPen
Drug ClassAnticholinergic
Controlled Substance ClassificationNot a controlled medication
Generic StatusNo lower-cost generic available
AvailabilityPrescription only
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What are the side effects of AtroPen (atropine)?

The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.

Common Side Effects

  • Pain at the site of injection
  • Dry mouth
  • Dry eyes
  • Blurry vision
  • Sensitivity to light
  • Confusion
  • Headache
  • Dizziness
  • Fast heart rate or other abnormal heartbeat
  • Flushing (blushing)
  • Stomach pain or discomfort
  • Nausea or vomiting
  • Constipation
  • Difficulty urinating
  • Low sex drive
  • Erection problems

Other Side Effects

  • Unable to sweat normally
  • Difficulty swallowing
  • Glaucoma
  • Rash

Serious Side Effects

Contact your healthcare provider immediately if you experience any of the following.
  • Overheating (hyperthermia)
  • Severe allergic reaction: trouble breathing; hives; swelling of the lips, tongue, or face

Source: DailyMed

pros-and-cons

Pros and cons of AtroPen (atropine)

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Pros

Can be used for people of all ages

Can inject through clothing

Pen is prefilled and ready to inject

Can be self-injected or injected by someone else if a provider isn't available

Works well to reverse poisoning from insecticides (pesticides) and certain nerve agents (in the event of war or act of terrorism)

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Cons

Dose might be complicated since it depends on age, weight, and symptoms

Might need up to three injections, one after another

Still need medical help after injections are given

Can cause many unpleasant side effects (e.g., dry mouth, blurry vision, dizziness)

Unknown if safe in pregnant females

pharmacist-tips

Pharmacist tips for AtroPen (atropine)

pharmacist

  • Wear proper protective clothing and specially-made masks to protect yourself from insecticide poisoning and chemical nerve agents. Clothing helps protect your skin, and goggles and masks help protect your face and eyes. AtroPen (atropine) can help treat your poisoning, but can't provide complete protection.

    • AtroPen (atropine) is the first emergency treatment you'll get, but you'll still need to see a provider for additional care. Get medical help right away after your injections so you can get other treatments for your poisoning.

      • If you or your caregiver are prescribed AtroPen (atropine) to give the injections at home, make sure you go over the instructions on how to give the injections properly. Know when to give the injections and how many injections to give. Ask your pharmacist or provider if you have any questions.

        • AtroPen (atropine) is an autoinjector, which means once you firmly jab the black or green tip against the thigh, the medication will automatically come out. It's important to hold the pen in place against the thigh for at least 10 seconds to get the full dose.

          • Don't put your fingers on the black tip of the 0.25 mg pen, or the green tip of the 0.5 mg, 1 mg, or 2 mg pens. This tip is where the needle will come out. Once the AtroPen (atropine) pen has been activated, the needle won't go back in.

            • Use a new AtroPen (atropine) pen for each injection. You might need three pens for your treatment if you need three injections of medication.

              • You might be monitored for at least 48 to 72 hours after AtroPen (atropine) your treatment.

                • Avoid being in a hot environment or exercising too much because AtroPen (atropine) can prevent you from sweating and raise your risk of overheating.

                  faqs

                  Frequently asked questions about AtroPen (atropine)

                  Who can give AtroPen (atropine) injections?
                  In general, AtroPen (atropine) should be given by someone who has proper training on how to recognize and treat insecticide or nerve agent poisoning. If a trained provider isn't available, AtroPen (atropine) can be given by yourself or a caregiver.
                  How do you know if someone experienced organophosphate or carbamate poisoning and might need AtroPen (atropine)?
                  Go over the signs and symptoms of organophosphate or carbamate poisoning with your provider. You or your caregiver must know what to look for and when to give AtroPen (atropine) if a provider isn't available. In general, mild symptoms can include blurry vision; small pupils; unexplained, excessive, watery eyes, runny nose, or drooling; difficulty breathing; coughing; muscle twitching; nausea; vomiting; stomach stomach cramps; or changes in heart rate (fast or slow). Severe symptoms can include strange or confused behavior, severe difficulty breathing, severe muscle twitching and general weakness, involuntary urination or bowel movements (passing stool), seizures, or passing out. Sometimes, healthy babies or young children who don't have poisoning can have some of these symptoms (e.g., watery eyes, runny nose, drooling, involuntary urination). So make sure to look at the overall symptoms if you suspect poisoning.
                  Can AtroPen (atropine) be given to anyone?
                  AtroPen (atropine) is approved for adults and children of all ages. But children might experience certain side effects earlier and with a lower dose compared to adults. In addition, overheating might be more noticeable in babies and small children. Older adults might also be at a higher risk for side effects because AtroPen (atropine) can take longer to clear out of their body. Because of this, people 65 years or older might need AtroPen (atropine) injections less often after the first dose is given. Speak to your provider to determine the proper dose for your age, weight, and symptoms.
                  Where can AtroPen (atropine) be injected?
                  AtroPen (atropine) is injected intramuscularly (into the muscle) into the outer thigh. You can inject through clothing, but make sure you remember to empty the pockets at the injection area. For small children or people who don't have a lot of fat at the injection area, you can pinch a fold of skin on the outer thigh. This creates a thicker area for injection.
                  What happens if AtroPen (atropine) is injected into a person who doesn't have any poisoning?
                  Giving AtroPen (atropine) injections by mistake to people who don't have poisoning can cause an overdose of atropine. Depending on how much was accidentally given, this can lead to trouble seeing or walking of varying severity, which can last for several hours. People who have heart problems are at a higher risk for serious side effects, including death. It's very important to give AtroPen (atropine) only when there's a known or suspected poisoning from an insecticide or nerve agent. Discuss with your provider about what you should look for in these situations.
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                  What are the risks and warnings for AtroPen (atropine)?

                  AtroPen (atropine) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.

                  risk-warning

                  Risk of heart problems

                  • Risk factors: Heart problems

                    AtroPen (atropine) might raise the risk of heart problems, which can include problems with heart rate, heartbeat, electrical activity, or blood flow. People who currently have heart problems or have had a recent heart attack might have a higher risk for heart damage. Let your provider know if you have any history of heart problems. They can determine if AtroPen (atropine) is right for you or monitor you more closely after using the medication.

                    risk-warning

                    Overheating

                    • Risk factors: Warm environment | Too much exercise

                      AtroPen (atropine) can prevent the body from sweating normally. In a warm environment or with too much exercise, your body can overheat and experience a heat-related problem. If possible, avoid being in the heat or exercising for too long after getting treated with AtroPen (atropine).

                      risk-warning

                      Acute (sudden) glaucoma

                      • Risk factors: Severe narrow-angle glaucoma

                        AtroPen (atropine) might cause sudden glaucoma. Your provider will monitor for signs and symptoms of increased eye pressure. Let them know if you have any eye pain, eye discomfort, or changes to your vision.

                        risk-warning

                        Trouble urinating

                        • Risk factors: Blockage of the bladder

                          AtroPen (atropine) might cause urinary retention, which is when the bladder has trouble emptying completely. Let your provider know if you have any difficulty urinating, or if you have any history of urinary problems that might get worse with this medication.

                          risk-warning

                          Intestine problems

                          • Risk factors: Pyloric stenosis

                            AtroPen (atropine) might worsen certain intestine problems, such as partial pyloric stenosis (narrowing of the pylorus or the opening from the stomach into the small intestine). This medication could cause a complete block of the pylorus. Let your provider know if you have any intestine problems before your treatment (if possible), or if you experience any stomach pain or problems after your treatment.

                            risk-warning

                            Sudden worsening of lung problems

                            • Risk factors: Long-term lung problems

                              AtroPen (atropine) might cause the mucus in your lungs to be thick and sticky, which can block your airways. If you have a lung or breathing problem, this can be especially dangerous. Your provider will monitor your lungs and airways after your AtroPen (atropine) treatment. Let your provider know right away if you have any difficulty breathing or shortness of breath.

                              risk-warning

                              Allergic reactions

                              Rarely, AtroPen (atropine) can cause an allergic reaction, including anaphylaxis. If you've had an allergic reaction to atropine in the past, you should be supervised by a medical provider before using AtroPen (atropine) if possible. Get medical help right away if you have any signs or symptoms of an allergic reaction, such as hives; difficulty breathing; or swelling of the eyes, mouth, or throat.

                              dosage

                              AtroPen (atropine) dosage forms

                              Typical dosing for AtroPen (atropine)

                              Prefilled AtroPen (atropine) autoinjectors are available in several dosage strengths: 0.25 mg, 0.5 mg, 1 mg, and 2 mg. Your dosage strength is based on your age and body weight. Your dose can be given up to three times depending on how severe your symptoms are.

                              In general:

                              • Mild symptoms: If there are at least two mild symptoms, give 1 AtroPen (atropine) injection into the muscle of the outer thigh. If there are any severe symptoms after the first injection, give 2 more AtroPen (atropine) injections into the muscle of the outer thigh quickly, one right after the other. Use a new pen for each injection.

                              • Severe symptoms: If unconscious (passed out) or if there are any severe symptoms, give 3 AtroPen (atropine) injections into the muscle of the outer thigh quickly, one right after the other. Use a new pen for each injection.

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