Omeprazole/Cimetidine Paste

Paste medications are thick and sticky, usually given by mouth using a syringe or tube. They’re often used for dewormers or other oral meds in horses, dogs, and cats. The key is to aim for the back of the mouth so your pet swallows the paste instead of spitting it out.

For Horses:

1. Set the dose on the syringe if it has markings (usually based on weight).
2. Stand beside your horse, not in front, and have someone hold them if possible.
3. Gently insert your thumb into the side of the horse’s mouth (between the teeth) to open it.
4. Insert the syringe into that gap and squirt the paste toward the back of the tongue.
5. Lift the horse’s head slightly and encourage swallowing by stroking the throat or gently blowing on the nostrils.
6. Watch for licking or chewing—that means they swallowed. If paste spills out, check how much was lost and contact your vet if unsure.
7. You can offer a little water afterward and reward them with a treat like a carrot if allowed.

For Dogs & Cats:

1. Gently open your pet’s mouth or slip the syringe into the side of it.
2. Aim toward the back of the tongue and squirt the paste in.
3. Hold the mouth closed briefly, and rub the throat or blow gently on the nose to encourage swallowing.
4. Give praise or a treat afterward to make it a positive experience.

Aftercare:

1. Wipe your pet’s mouth if needed.
2. Clean or recap the syringe as instructed.
3. Store the tube according to label directions.

Tip: Paste can feel weird to pets at first. For horses, try giving applesauce by syringe ahead of time so they get used to the sensation.

This compounded formulation combines omeprazole, a proton pump inhibitor, with cimetidine, an H2-receptor antagonist — two different drug classes. In compounding practice, clinicians may consider a combination like this for a multi-targeted approach. Your veterinarian determines whether it is appropriate based on your animal's diagnostic findings.

At a pharmacological level, omeprazole acts as a proton pump inhibitor by irreversibly binding to the hydrogen-potassium ATPase enzyme system within the gastric parietal cells. This action suppresses the final step of acid secretion into the stomach lumen. Cimetidine acts as an H2 receptor antagonist by competitively inhibiting histamine at the receptors of the parietal cells. While both medications serve to manage acid levels, they act on different stages of the secretory process. This combination is intended to address the gastric environment through complementary mechanisms, providing a broader profile of acid modulation. Your veterinarian will determine if this specific combination is appropriate based on your horse's history, activity level and diagnostic findings.

This description reflects the general pharmacology of the active ingredient's drug class; your veterinarian determines whether this approach is appropriate for your animal.

Prescription only. Use only under the direction of a licensed veterinarian. This information is not a substitute for veterinary diagnosis, prescribing or monitoring. Compounded drugs are not approved by the FDA for safety or effectiveness.

Commonly observed effects of omeprazole/cimetidine may include mild gastrointestinal changes such as loose stools or transient changes in appetite shortly after administration. Because cimetidine is known to inhibit certain hepatic microsomal enzymes, it may influence the metabolism of other medications. Your veterinarian will monitor for potential medication interactions and may recommend specific timing for administration if your horse is receiving other prescriptions.

This medication is typically used with caution in patients with known liver or kidney impairment, as these systems are responsible for the processing and excretion of the active ingredients. It is essential to provide your veterinarian with a complete history of all other medications and supplements your horse is receiving, as the alteration of gastric pH can influence the absorption of other oral treatments. Always follow the professional guidance provided by your veterinarian regarding the duration of use and any necessary patient monitoring. Contact your veterinarian promptly if you observe significant behavioral changes, persistent diarrhea or any signs of physical discomfort during the administration period.