Allergy to glucagon is the direct contraindication for treating hypoglycemia.

What is a contraindication for administering glucagon?

• A. Recent head injury
• B. Allergy
• C. History of diabetes
• D. Hypertension

Answer: (B)

Administering glucagon has a specific contraindication: any known allergy to the medication itself. Allergic reactions can lead to serious complications, including anaphylaxis, which is a life-threatening emergency. When a patient has a confirmed allergy to glucagon, the risks of administering the drug outweigh the potential benefits for treating hypoglycemia. While other options might involve medical considerations, they do not directly prevent the use of glucagon in the same way as a documented allergy does. For example, recent head injury may affect consciousness or the ability to swallow, but it doesn’t inherently negate glucagon’s action in managing low blood sugar levels. Similarly, a history of diabetes indicates a potential need for glucagon but does not serve as a contraindication. In contrast, hypertension is a common condition and typically does not impact the administration of glucagon. Thus, the mention of an allergy specifically highlights a critical and direct reason to refrain from using glucagon in treatment.

What blocks glucagon? A quick, practical guide for EMTs

When you roll up on a patient who’s pale, sweaty, and possibly hypoglycemic, glucagon is one of those tools that can flip the script fast. It’s a simple idea: if someone’s blood sugar is dangerously low and there’s no easy way to get glucose into them right away, glucagon can kick in and spark a rise in sugar. But there’s one hard-and-fast rule you should never forget: if there’s a known allergy to glucagon or to any ingredient in the product, you do not give it. The adage “the risks outweigh the benefits” isn’t just medical jargon here—it’s life-saving common sense.

Let me explain why this one rule matters so much, and what that means in the field.

Allergic allergy: the one real contraindication

Here’s the thing about glucagon: it’s a peptide hormone. For some folks, even a seemingly small exposure can spark a reaction. An allergy to glucagon or to one of the other ingredients in the medication makes the risk of an allergic reaction—hives, swelling, trouble breathing, or worse—outweigh any potential benefit from rapidly treating low blood sugar. When a patient has a confirmed allergy, it’s not just a caution; it’s a clear contraindication.

You might be wondering about the other options on a multiple-choice question like this. A recent head injury? History of diabetes? Hypertension? These are important clinical notes, but they don’t automatically ban glucagon’s use in the same way. Let’s unpack that a bit so it’s clear how to think through it in the moment.

Recent head injury

A head injury can complicate a lot of decisions. The tricky part is: does it stop glucagon from working? Not exactly. Head injuries can affect consciousness or swallowing, which might lead you to choose routes for glucose delivery that are safer (like IV dextrose when available, or ensuring airway protection). But a known head injury by itself doesn’t negate glucagon’s mechanism of action against hypoglycemia. The key is to assess the patient’s airway, circulation, and ability to protect their airway, then decide on the safest route to raise blood sugar.

History of diabetes

Paradoxically, a patient with diabetes is exactly the person glucagon is meant to help—when they’re unable to take oral glucose and IV access isn’t immediately available. A history of diabetes is not a contraindication; it’s often a signal you’re in the right neighborhood for glucagon use, provided there isn’t an allergy. The goal is to restore glucose quickly so the patient can regain their baseline mental status and protection of airway. If you’re uncertain about the patient’s baseline, you follow protocol, monitor vitals, and proceed with the safest proven option available.

Hypertension

High blood pressure generally doesn’t prevent glucagon from being used. It’s a systemic condition that you’ll manage as part of the bigger picture, but it doesn’t block glucagon’s ability to stimulate glycogen breakdown and raise blood sugar in the moment. Of course, you still manage the patient with a calm, careful hand—watch for signs of other complications and treat the hypoglycemia first if it’s safe to do so.

What to do in the moment: practical steps for EMTs

• Check allergies first. If the patient (or a caregiver) clearly states an allergy to glucagon or to any component of the product, you do not administer it. In the field, you’ll often screen with a quick question to family members or piece together a medical bracelet. If there’s doubt about allergy, you may choose to use other methods to raise blood sugar if available and appropriate.

• Confirm the patient’s airway status. If the patient is unconscious or vomiting, ensure airway protection. Glucagon is typically given intramuscularly or subcutaneously, which can still be appropriate when IV access isn’t ready, but airway safety comes first.

• Evaluate alternatives. If glucagon cannot be given due to allergy, or if there’s a failure to respond, you switch to the safest adjacent option: oral glucose if the patient is awake and able to swallow, or intravenous dextrose if IV access is available and the patient can be connected safely. Your goal is to raise blood sugar while maintaining a clear airway.

• Documentation matters. Note the allergy status clearly in the patient care report, including what was given, and how the patient responded. If you had to skip glucagon due to allergy, document that decision and the rationale. Clear notes help everyone downstream—nurses, physicians, and EMS partners.

What this means for real-world care

In the field, you’re not just following a checklist; you’re making a quick, high-stakes judgement call. The answer to “what is a contraindication for administering glucagon?” is simple in concept: an allergy to glucagon or its ingredients. The implications are nuanced in practice, which is exactly why you practice the scenario in your mind before you’re in it.

Think of it like this: glucagon is a rescue tool for when the body’s pantry is running low on glucose, and you’re trying to get sugar into the bloodstream without an immediate IV line. An allergy is a door that won’t open, no matter how hungry the patient is. When that door is shut, you pivot to other safe routes to glucose, while keeping the patient’s airway clear and monitoring for any signs of deterioration.

A few quick reminders to keep you sharp on the street

• Always check for allergies to glucagon or any formulated components. If there’s a known allergy, don’t use it.

• Remember that the other options aren’t “wrong,” they’re just not the same thing as giving glucagon. Use what’s safest and most effective given the circumstances.

• Maintain airway and monitor mental status. Hypoglycemia can worsen quickly if not treated, but improper airway management can create new problems.

• Use real-world resources. Brand names like GlucaGen are common references, but the essential principle is the contraindication itself: allergy.

• Keep your team in the loop. Share your assessment and rationale when you hand off, so the next care providers can pick up smoothly.

A little context to make it stick

Glucagon is a handy tool because it can work even when IV access is delayed or difficult. That’s the practical reason it’s a staple in many emergency medical kits. But tools have boundaries, and contraindications are those boundaries. It’s a bit of field wisdom: you respect the allergy, you adapt the plan, you keep the patient’s safety at the center of every decision.

If you’ve ever stood at the doorway of a patient’s life, where a millisecond of hesitation could tilt the outcome, you know why this matters. It’s not about memorizing a marathon of facts; it’s about recognizing a red line and choosing the safest path forward. That’s what makes a good EMT not just technically competent, but grounded in patient-centered care.

Bringing it home

The one clear contraindication for administering glucagon is a known allergy to the medication or its components. Everything else—head injury, diabetes history, hypertension—may guide your approach, but they don’t automatically prevent use in all cases. In the field, you’ll use your training, your instincts, and your teamwork to navigate these nuances.

If you’re faced with a hypoglycemic patient and you’re weighing glucagon, pause for a breath, confirm the allergy status, assess the airway, and choose the safest path to raise the blood sugar. And if glucagon can’t be given, you’ve got other tools in your kit—oral glucose for a responsive patient, or IV dextrose when an IV line is at hand. The patient’s safety isn’t a single move; it’s a sequence of careful, connected actions.

So next time you read a case like this, you’ll remember the simple rule and the bigger picture. Allergy to glucagon is the real contraindication. Everything else is about choosing the best route for that moment—one that keeps the patient calm, the brain stable, and the line of care clear for the next responder. After all, in emergency medicine, clarity and composure are often as important as the medicine you carry.