Valacyclovir and Fentanyl-100 drug interactions - a phase IV clinical study of FDA data

Summary:

Drug interactions are reported among people who take Valacyclovir (valacyclovir hydrochloride) and Fentanyl-100 (fentanyl). Common drug interactions include pyrexia among females and disturbance in attention among males.

The phase IV clinical study analyzes what interactions people have when they take Valacyclovir and Fentanyl-100. It is created by eHealthMe based on reports of 8 people who take the same drugs from the FDA, and is updated regularly.

What is Valacyclovir?

Valacyclovir has active ingredients of valacyclovir hydrochloride. It is often used in genital herpes. eHealthMe is studying from 42,107 Valacyclovir users. Check the latest studies of Valacyclovir.

What is Fentanyl-100?

Fentanyl-100 has active ingredients of fentanyl. It is often used in pain. eHealthMe is studying from 7,047 Fentanyl-100 users. Check the latest studies of Fentanyl-100.

On Jun, 11, 2026

8 people who take Valacyclovir and Fentanyl-100 together, and have interactions are studied.

Valacyclovir and Fentanyl-100 drug interactions.

What are the common drug interactions of Valacyclovir and Fentanyl-100, by gender? *:

female:

Pyrexia (fever)
Upper respiratory tract infection
Acute graft versus host disease in skin (acute complication on skin following an allogeneic tissue/blood transplant)
Acute pulmonary oedema (sudden deposit of fluid in the lung))
Aphasia (damage to the parts of the brain that control language)
Ataxia (loss of full control of bodily movements)
Atrial fibrillation (fibrillation of the muscles of the atria of the heart)
Chills (felling of cold)
Cytomegalovirus test positive
Diarrhoea

male:

Disturbance in attention
Fall
Malaise (a feeling of general discomfort or uneasiness)
Muscular weakness (muscle weakness)
Neuralgia (pain in one or more nerves)
Peripheral sensory neuropathy (damage to one or more of your peripheral nerves)

What are the common drug interactions of Valacyclovir and Fentanyl-100, by age (0-1 to 60+)? *:

0-1:

n/a

2-9:

n/a

10-19:

n/a

20-29:

n/a

30-39:

n/a

40-49:

Acute graft versus host disease in skin (acute complication on skin following an allogeneic tissue/blood transplant)
Aphasia (damage to the parts of the brain that control language)
Ataxia (loss of full control of bodily movements)
Atrial fibrillation (fibrillation of the muscles of the atria of the heart)
Chills (felling of cold)
Cytomegalovirus test positive
Diarrhoea
Dizziness
Fall
Head injury

50-59:

Neuralgia (pain in one or more nerves)
Peripheral sensory neuropathy (damage to one or more of your peripheral nerves)
Protein urine present
Upper respiratory tract infection
Malaise (a feeling of general discomfort or uneasiness)
Disturbance in attention
Fall
Light chain analysis increased
Lung neoplasm (tumour of lung)
Monoclonal immunoglobulin present

60+:

Embolism (obstruction of an artery, typically by a clot of blood or an air bubble)
Haemoptysis (blood-stained sputum from the bronchi, larynx, trachea, or lungs)
Lung adenocarcinoma stage iv (the cancer has spread to other organs of the body, such as the other lung, brain, or liver)

* Approximation only. Some reports may have incomplete information.

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