What to Expect at a Vivitrol Injection Appointment
A Vivitrol appointment runs 30 to 90 minutes total. Most of that is paperwork, vital signs, and observation, not the injection itself. The shot takes about 5 minutes. The rest is the structure that makes the medication work safely.
Before you go
Bring your ID and insurance card. Bring a list of any medications you are taking, including over-the-counter pain medications. Wear loose pants or a skirt - the injection goes into the gluteal muscle, so loose-waisted bottoms make access easier.
Eat normally. There are no pre-injection food or fluid restrictions. Hydration is encouraged.
For the first appointment, expect to be there 60 to 90 minutes. For follow-up monthly visits, 30 to 45 minutes.
Check-in and intake
Standard medical office check-in. Insurance verification, paperwork, intake questions. The medical assistant takes vital signs (blood pressure, heart rate, weight) and asks about any new substance use or symptoms since the last visit.
For the first appointment, expect a longer history: substance use timeline, prior treatment, medical comorbidities, mental health history, current medications. The provider may also do a brief physical exam.
The provider visit
Most Vivitrol providers see the patient briefly before each injection, even at follow-up visits. The visit typically covers: how things have been going since the last shot, any side effects, any breakthrough cravings or use, any life changes affecting treatment, and any concerns about the upcoming month.
For the first appointment, this is also when the prescriber confirms eligibility for Vivitrol. They may do a naloxone challenge test (small dose of naloxone, observation for 30 to 60 minutes) to confirm the patient is opioid-free if they are starting Vivitrol for opioid use disorder.
The injection itself
A nurse or medical assistant prepares the medication. Vivitrol comes in a kit with the medication, diluent, and a special needle for the deeper IM injection. The medication is mixed in front of the patient.
The patient is positioned face-down on the exam table or standing leaning forward against the table. The nurse cleans the gluteal injection site with alcohol. The injection itself takes about 30 seconds. Most patients describe it as a deeper, slower stick than a flu shot, but not particularly painful.
The injection alternates sides month to month. Right gluteal, then left, then right.
Post-injection observation
For the first injection, most clinics observe the patient for 30 to 60 minutes after the shot to monitor for any precipitated withdrawal symptoms. This is the safety net for the rare case where a patient passed the naloxone challenge but still has subclinical opioid receptor occupancy.
For follow-up monthly injections, observation is typically 15 to 30 minutes or skipped entirely depending on the clinic.
Going home
Patients can drive home. There are no restrictions on activity, work, or exercise. Most prescribers recommend avoiding strenuous lower-body exercise for 24 hours to reduce muscle soreness, but this is comfort-driven, not medically required.
The patient leaves with a follow-up appointment scheduled for 4 weeks later, contact information for the clinic, and any prescriptions for adjunct medications (sleep aids, anxiety management, etc.) the prescriber thinks are appropriate.
Common side effects timeline
Days 1 to 3: injection site soreness is most common. Sometimes a hard lump forms at the injection site. This is normal and resolves over 1 to 2 weeks. Mild nausea, headache, or fatigue can occur.
Week 1: some patients experience mood changes, sleep disturbance, or appetite changes. Most resolve as the body adjusts. The prescriber should be informed if these are severe.
Weeks 2 to 4: stable on the medication. The therapeutic effect is fully active. This is the period during which the medication is doing its work.
Day 28: next injection. The medication's blood level is at its lowest point of the cycle. Some patients describe noticing a subtle return of cravings in the days before the next shot. Not universal but worth tracking.
Things to watch for
Severe injection site reaction (extensive swelling, redness extending beyond the injection site, fever): contact the prescriber immediately. Rare but documented complications can occur.
Symptoms of liver problems (jaundice, dark urine, severe fatigue, abdominal pain): contact the prescriber. Naltrexone has hepatotoxicity warnings, especially at higher doses. Most prescribers do periodic LFTs.
Severe depression or suicidal thinking: contact the prescriber. Vivitrol can be associated with mood changes in some patients, and it is important to differentiate medication-related effects from treatment of the underlying condition.
Pain management situations
Patients on Vivitrol cannot effectively use opioid pain medications. Naltrexone blocks the opioid receptors. For minor pain, NSAIDs and acetaminophen are usually adequate. For surgery or dental work, the patient needs to plan with their surgeon. Options include non-opioid anesthesia, regional blocks, ketamine, or temporarily stopping Vivitrol if the procedure can be timed accordingly.
Wear a medical alert bracelet or carry a Vivitrol identification card. In an emergency where opioid pain management is needed, the medical team needs to know.
If you miss an appointment
Call the clinic immediately and reschedule. The medication's effect tapers over the second 28-day window. By 35 to 45 days after the last shot, opioid receptors are mostly back online. The earlier you can reschedule, the better.
If you are coming back late after a missed appointment for opioid use disorder treatment, the prescriber may need to confirm you are still opioid-free before giving the next shot. Plan for that conversation.