What Happens After You Report an Adverse Event to NAFDAC?

Primary sources: NAFDAC Good Pharmacovigilance Practice Guidelines; NAFDAC guidance on handling adverse drug reactions; WHO Programme for International Drug Monitoring

Quick answer: After an adverse event is reported to NAFDAC, the report enters the national pharmacovigilance process. It is checked for validity and completeness, entered as an Individual Case Safety Report, coded and assessed, and followed up where important information is missing. The case then joins Nigeria's national safety dataset and is shared into the World Health Organization global database, where it is reviewed alongside other reports for emerging safety signals. Where the accumulated evidence supports it, the information can contribute to regulatory action such as further investigation, safety communication, a change to product information, or restriction of a product. A single report is safety information. It is not, on its own, a finding that a medicine is unsafe.

What counts as an adverse event?

Before tracing what happens to a report, it helps to be precise about what has actually been reported. The terminology matters, because it determines how the case is classified and what NAFDAC can do with it.

Adverse event compared with adverse drug reaction

An adverse event is any untoward medical occurrence in a patient who has been given a medicinal product. It does not need to have a causal relationship with the product. It is, in plain terms, something bad that happened while the patient was on treatment. An adverse drug reaction is narrower: it involves a suspected causal relationship between the product and the event. NAFDAC's public guidance on handling adverse drug reactions adopts the World Health Organization definition of an ADR as a harmful and unintended response to a medicine occurring at doses normally used in humans for prevention, diagnosis or treatment of disease, or for modifying physiological function. MedNova's glossary entry on the adverse drug reaction sets out the definition in short form.

The distinction is not academic. It explains why a report is not an accusation. Reporters are asked to report suspicion, not proof. Establishing causality is the assessment work that comes afterwards, and it is performed on the evidence, not on the reporter's certainty.

Why NAFDAC collects adverse event reports

Nigeria's pharmacovigilance system exists to protect patients from harm that clinical trials could not have detected. Trials are small, short, and run in restricted populations. Real world use is large, long, and messy. NAFDAC's Good Pharmacovigilance Practice Guidelines set out the quality objectives of a pharmacovigilance system in exactly those terms: complying with legal obligations, preventing harm from adverse reactions including harm from off label use, misuse, abuse, medication error and occupational exposure, promoting safe and effective use through timely safety information, and contributing to the protection of patients and public health.

The practical objectives your report serves are:

Detecting risks that were not visible before the product reached the market
Identifying patterns across multiple patients that no single clinician would see
Refining the known safety profile of a product used in Nigerian patients specifically
Supporting benefit to risk evaluation, which is the question that ultimately decides whether a product stays on the market unchanged
Informing safety communication to prescribers, pharmacists and patients

Does reporting mean the medicine caused the reaction? No. Reporting a suspected adverse event does not establish that the medicine caused it. A report records an association in time and a clinical suspicion. Causality assessment is a separate, structured step performed later, and many reported events turn out to be explained by the underlying disease, a concomitant medicine, or an unrelated condition. Reporters should never withhold a report because they are unsure of the cause. Uncertainty is the normal state of a safety report at the point of submission.

What happens after you submit the report to NAFDAC?

Direct answer: The report is received through the reporting channel used, validated and checked for completeness, entered and coded as an Individual Case Safety Report, assessed, followed up where necessary, added to Nigeria's national safety database and the global database, and reviewed in aggregate for safety signals. Regulatory action follows only where the accumulated evidence supports it.

Below is what happens at each stage.

Step 1

The report is received

Nigeria uses several intake routes, coordinated by the National Pharmacovigilance Centre within NAFDAC's Pharmacovigilance and Post Marketing Surveillance Directorate. ADRs are reported on ADR forms (yellow forms or ICSR forms) available through NAFDAC's state offices across the 36 states, the National Pharmacovigilance Centre at NAFDAC headquarters in Wuse Zone 7, Abuja, and zonal pharmacovigilance centres hosted at ABUTH Shika, Federal Medical Centre Owerri, LUTH Lagos, UBTH Benin, UITH Ilorin and UMTH Maiduguri. NAFDAC also operates an ADR e-reporting form online, and the Med Safety mobile application is in use for direct reporting. Which route you used affects how quickly the information becomes structured data, but not whether it counts.

Step 2

The report is validated and checked for completeness

Validation asks a simple question: does this report contain enough information to be treated as a real safety case? The internationally applied minimum criteria, which NAFDAC's framework reflects, are four: an identifiable patient, an identifiable reporter, a suspect product, and a suspected adverse reaction or event. If any of the four is missing, the report cannot yet be processed as a valid case. This is the single most common reason a report stalls, and it is entirely preventable at the point of submission.

Step 3

The case is entered, coded and assessed

A valid report is entered into the national safety database, coded using standardised medical terminology, and checked against existing records so the same case reported through two channels is not counted twice. NAFDAC's guideline treats the full chain — collection, processing, quality control, follow up, coding, classification, duplicate detection, evaluation and timely transmission — as a critical pharmacovigilance process. Assessment then looks at seriousness, expectedness against what is already known about the product, and the plausibility of a causal relationship. See MedNova's PV Readiness Guide for how these operations fit together.

Step 4

Follow up is requested where information is missing

If the case cannot be properly evaluated as submitted, follow up is sought. This is why reporter contact details matter so much. A case with a clear clinical picture, dates, outcome and product details is a usable safety signal contributor. The same case without an outcome or a suspect product name is close to unusable.

Step 5

The case joins the national and global safety dataset

Nigeria has been a member of the WHO Programme for International Drug Monitoring since 2004. National reports are managed in VigiFlow, the ICSR management system provided by the Uppsala Monitoring Centre, and transmitted into VigiBase, the WHO global database of individual case safety reports. This is the step most reporters are unaware of, and it is the one that gives a single Nigerian report disproportionate value — a rare event reported three times in Nigeria may be invisible nationally and highly visible globally. Reports in VigiFlow rose from 2,051 in the baseline period to 18,995 after the Med Safety App was deployed, with 81.7% of post-deployment reports arriving through the app and paper-based reporting falling from 98.4% to 15.7%.

Step 6

The data is reviewed for signals

Individual case assessment answers a question about one patient. Signal detection answers a question about a product. Reports are reviewed in aggregate to identify patterns: repeated events of the same type, unexpected events not described in the product information, events clustered in a particular population, or a rate that appears higher than background. A validated signal then goes through assessment to determine whether the evidence genuinely supports a new or changed risk.

Step 7

Regulatory action where the evidence supports it

Only at this point does regulatory action become possible, and the form it takes depends on the strength of the evidence, seriousness and frequency, and the product's overall benefit to risk position. Possible outcomes include continued monitoring, a request for additional safety information, a post-authorisation safety study, safety communication, changes to product information or the risk management plan, additional risk minimisation measures, or restriction, suspension or withdrawal where warranted. There is no fixed number of reports that automatically triggers any of these.

What is an ICSR and why does it matter?

An Individual Case Safety Report is the structured record of a single patient's suspected adverse reaction to one or more products. It is the basic unit of pharmacovigilance data worldwide, and the format in which Nigeria's reports travel to the WHO global database.

What information an ICSR normally captures

An identifiable patient, with age, sex and relevant characteristics where available
An identifiable reporter, with contact details enabling follow up
The suspect product, ideally including brand name, batch or lot number and manufacturer
The suspected adverse event or reaction, described clinically
Dates of treatment start, event onset and any resolution
Dose, route and indication where known
Clinical outcome, including whether the patient recovered
Concomitant medicines, including traditional and over the counter products
Relevant medical history and comorbidities
Laboratory or diagnostic findings where available
Whether the event abated when the product was stopped, and recurred if it was restarted

Not every field is mandatory for a report to be accepted, and a report should never be delayed while chasing a complete dataset. But the more of these fields are present, the further the case travels through the process before it stalls.

Why incomplete reports need follow upTwo reports of the same event can have entirely different value. One says a patient developed a rash on an antibiotic. The other says a 34-year-old woman developed a widespread maculopapular rash on day three of a named antibiotic, with no concomitant medicines, which resolved within four days of stopping the drug. The first cannot support a causality assessment. The second can. Follow up exists to turn the first into the second.

Will NAFDAC contact you after you report an adverse event?

Direct answer: Possibly. Follow up occurs when additional information is needed to assess or clarify a case. It is not a routine acknowledgement service, and the absence of contact should not be read as the report having been discarded. Follow up is targeted at cases where more detail would change what can be concluded.

What information might be requested

Additional clinical detail on the presentation and course of the event
Treatment start and stop dates, and the timing of onset relative to the dose
The clinical outcome, including recovery, sequelae or death
Laboratory results, imaging or other diagnostic findings
Product details such as brand, batch or lot number and expiry
Dose, frequency and route
Concomitant medicines and relevant medical history
Supporting documentation such as discharge summaries where appropriate

Who should coordinate the response inside a company

For a Certificate of Registration Holder, the response is not an ad hoc task for whoever opens the email. NAFDAC's guideline requires the Qualified Person Responsible for Pharmacovigilance to act as the single pharmacovigilance contact point for the Agency on a 24 hour basis and as the contact point for pharmacovigilance inspections, and requires the company to put a procedure in place so the QPPV can obtain information from the safety database to answer urgent Agency requests at any time.

The guideline also requires the QPPV to reside and operate in Nigeria. Companies without a functioning QPPV in Nigeria typically discover the gap at exactly the wrong moment, which is when NAFDAC asks a time-bound question. MedNova provides outsourced QPPV and local safety representation, and sets out the governance expectations in our QPPV Support Essentials guidance.

What happens if the adverse event is serious?

Serious cases are prioritised, processed on shorter timelines and scrutinised more closely, because they carry the greatest patient safety weight and the greatest regulatory consequence.

Serious is not the same as severe

This is one of the most persistent confusions in pharmacovigilance, and it changes how a case is handled. Severity describes the intensity of an event. A severe headache is intense but usually not serious. Seriousness is a regulatory classification based on outcome. Under the internationally applied criteria set out in ICH E2A, an event is serious if it results in death, is life threatening, requires hospitalisation or prolongs an existing hospitalisation, results in persistent or significant disability or incapacity, causes a congenital anomaly or birth defect, or is otherwise a medically important event.

Worked exampleA mild rash that leads to hospitalisation is serious. An excruciating but self-limiting headache is not. Getting this classification right is what determines the reporting timeline a company must meet.

On timelines, NAFDAC's own performance expectations make the structure visible: the Pharmacovigilance System Master File must contain figures showing the timeliness of 15-day and 90-day reporting across the previous year, alongside metrics on the quality of submissions. That reflects the standard expedited and non-expedited split, with serious valid cases on the shorter clock. Companies should confirm the applicable time frame for each case type against the current edition of the NAFDAC Good Pharmacovigilance Practice Guidelines rather than relying on internal custom.

How long does NAFDAC take to review an adverse event report?

Direct answer: There is no single published turnaround time that applies to every adverse event report submitted to NAFDAC. This is an important distinction that a great deal of online content gets wrong. The regulated deadlines in Nigerian pharmacovigilance are submission deadlines placed on companies, not review deadlines placed on the regulator.

How long assessment takes in any individual case depends on:

Whether the report met the minimum validity criteria on arrival
How complete the clinical, product and outcome information was
Whether follow up was required and how quickly the reporter responded
The seriousness of the event
The clinical complexity of the case and the plausibility of alternative explanations
Whether the case connects to an existing safety question already under evaluation
Whether the case forms part of a wider signal assessment, which operates on a longer horizon than case processing

For reporters, the practical implication is that a case can be actively contributing to safety monitoring long before, and often without, any individual communication back.

Does reporting an adverse event lead to a product recall?

No. A single adverse event report is safety information, not evidence that a product should be withdrawn. The chain runs: report, validation, assessment, follow up where needed, aggregation with other data, signal detection and evaluation, benefit to risk assessment, and regulatory decision where the evidence warrants it. Recall is one possible outcome at the end of that chain, and it is among the least common.

Far more frequently, safety information leads to a labelling change, a warning added to product information, a Direct Healthcare Professional Communication, a new risk minimisation measure, or a requirement for further study. Fear that a report will trigger a recall is one of the reasons reporting rates remain lower than they should be. It is not a well-founded fear.

Does one adverse event mean a medicine is unsafe?No. One report establishes that one patient experienced an event that someone suspected might be drug related. Safety conclusions come from patterns, not from single observations. The interpretive sequence is: an adverse event is something that happened, an adverse drug reaction involves a suspected causal link, a safety signal is information suggesting a new or changed causal association that warrants investigation, and a confirmed risk is a signal that assessment has substantiated. Most reports never progress beyond the first two stages, and that is the system working correctly rather than failing.

What you should do after submitting an adverse event report

If you are a healthcare professional or patient

Keep a record of what you submitted and when, including any reference number
Retain the relevant clinical notes and product details, including batch or lot number
Remain reachable at the contact details you provided
Respond promptly if additional information is requested
Submit a follow-up report if the outcome changes, for example if the patient recovers, deteriorates or is hospitalised
Do not assume silence means the report was ignored

If you are a Certificate of Registration Holder or Marketing Authorisation Holder

Confirm and archive the submission evidence, including date and channel
Record the receipt date that started the reporting clock
Document every follow-up attempt, whether or not it succeeded
Assess whether related cases exist in your own safety database
Reconcile the case against quality complaint and medical information records so nothing is lost at the interface
Feed the case into your signal detection cycle rather than closing it on submission
Include the case in the relevant aggregate report
Escalate internally where the case changes what you know about the product
Preserve a complete audit trail, because the case file is inspection evidence

A structured self-assessment against current NAFDAC expectations is available in MedNova's NAFDAC QPPV Compliance Checklist.

Download the Checklist PDF

What if you do not hear back from NAFDAC?

Silence is the normal outcome for most reports, and it is not a signal that anything went wrong. Reasonable steps if you want assurance or have more to add:

Retain your submission record and reference details
Submit a follow-up report if new clinical information becomes available, rather than resubmitting the original
Contact the National Pharmacovigilance Centre or your zonal pharmacovigilance centre through NAFDAC's published channels if you need to confirm receipt
For companies, route the query through the QPPV, who is the designated contact point for the Agency

Repeated resubmission of the same case is counterproductive. It creates duplicates that consume assessment capacity and can distort the apparent frequency of an event.

What this means for pharmaceutical companies operating in Nigeria

For companies, submission is not the end of an obligation. It is the start of one. NAFDAC's guideline places the pharmacovigilance system, not the individual report, at the centre of compliance, and a case file is only as defensible as the system that produced it.

The obligations that continue after submission include:

Maintaining traceability and the ability to follow up on every adverse reaction report
Responding fully and promptly to Agency requests for additional information
Monitoring and measuring your own reporting timeliness, with figures retained in the Pharmacovigilance System Master File
Detecting and managing signals arising from accumulating data
Keeping product information current with new safety knowledge
Maintaining records for the applicable retention period, protected from destruction
Auditing the system and closing corrective and preventive actions to demonstrated effectiveness

Companies that outsource case processing should note that delegated activity remains inside the boundary of their own pharmacovigilance system. NAFDAC's guideline requires detailed written agreements, a description of delegated services inside the master file, and a list of subcontracts in the annex, and permits the Agency to inspect the third party. The ultimate responsibility for the quality and integrity of the system never transfers. Our regulatory affairs services in Nigeria and clinical development support are structured around that principle. For the full picture of the regulatory framework behind these obligations, see our NAFDAC Pharmacovigilance Requirements guide.

Adverse event reporting in Nigeria: what healthcare professionals should know

Nigeria's safety data is generated overwhelmingly by clinicians, pharmacists and nurses at the point of care. A few points that materially improve the value of what you submit:

Report suspicion, not proof. If you wait for certainty, the report will never be made
Report events involving traditional, herbal and over the counter products as well as prescription medicines
Record the batch or lot number where you can. It is the single most useful field for distinguishing a product quality problem from a pharmacological reaction
Include concomitant medicines. Many reported events turn out to be interactions
Report the outcome, and follow up when it changes
Leave contact details. A report that cannot be followed up has a ceiling on its usefulness
Report events that are already known. Frequency data matters as much as novelty

Underreporting remains the principal constraint on pharmacovigilance in Nigeria, as it is in most countries. The rapid growth in reports following the introduction of digital reporting tools demonstrates that the constraint has been access and friction rather than willingness.

When to seek pharmacovigilance support in Nigeria

Adverse event follow up is where weak pharmacovigilance systems become visible, because it is the point at which the regulator asks a question with a clock attached. Companies typically need external support at one of the following moments:

Preparing to launch a product in Nigeria and needing a pharmacovigilance system before the first case arrives
Receiving a NAFDAC follow-up request and finding the source data cannot be retrieved quickly
Operating without a resident QPPV, or with one who lacks authority over the safety system
Holding a Pharmacovigilance System Master File that describes an intended system rather than the operating one
Processing cases without a signal detection cycle behind them
Facing a pharmacovigilance inspection without measured timeliness figures or closed corrective actions
Expanding from Nigeria into other African markets and needing the system to scale

MedNova Lifesciences provides pharmacovigilance services in Nigeria covering ICSR intake and case processing, aggregate reporting, signal detection and risk management, literature surveillance, PV system setup and SOPs, inspection readiness, and local QPPV representation. On the regulatory side we support NAFDAC product registration, market entry and compliance planning, dossier and registration preparation, variations, renewals and lifecycle management, and we run training and consulting for pharmacovigilance and regulatory teams.

Next step: read the regulatory affairs primer for the wider Nigerian regulatory picture, browse the full resources library, review our capability statement, or contact our team to discuss a pharmacovigilance compliance assessment.

Need help with adverse event follow-up?

MedNova Lifesciences supports companies with ICSR intake and case processing, signal detection, QPPV representation, and inspection-ready pharmacovigilance systems in Nigeria and across Africa.

Contact MedNova Lifesciences

Related resources

Frequently asked questions

What happens after reporting an adverse event to NAFDAC?

The report is received through the channel used, validated against minimum criteria, entered and coded as an Individual Case Safety Report, assessed for seriousness and causality, followed up where information is missing, and added to Nigeria's national safety dataset and the WHO global database. It is then reviewed alongside other reports for safety signals, and can contribute to regulatory action where the evidence supports it.

Will NAFDAC contact me after I submit an adverse event report?

Possibly. Follow up occurs where additional information is needed to assess or clarify the case, which is why contact details matter. Most reports do not generate individual correspondence, and silence does not mean the report was discarded.

How long does NAFDAC take to review an adverse event report?

There is no single published turnaround time covering every report. The regulated deadlines in Nigerian pharmacovigilance are submission deadlines placed on companies, not review deadlines placed on the Agency. Assessment time depends on completeness, seriousness, clinical complexity and whether follow up is required.

What is an ICSR in pharmacovigilance?

An Individual Case Safety Report is the structured record of one patient's suspected adverse reaction to one or more products. It is the standard unit of safety data internationally and the format in which Nigerian reports are transmitted to the WHO global database.

What happens if an adverse event report is incomplete?

It may not qualify as a valid case. The minimum criteria are an identifiable patient, an identifiable reporter, a suspect product and a suspected adverse event. Where these are present but clinical detail is thin, follow up may be sought to make the case assessable.

Can NAFDAC request additional information after an ADR report?

Yes. For companies, the Qualified Person Responsible for Pharmacovigilance is the designated contact point for the Agency on a 24 hour basis, and the company must have a procedure enabling the QPPV to retrieve safety database information to answer urgent requests at any time.

Does reporting an adverse event mean the medicine caused the reaction?

No. A report records a suspicion and a temporal association. Causality assessment is a separate structured step, and many reported events are ultimately explained by the underlying disease, a concomitant medicine or an unrelated condition.

Does one adverse event report result in a product recall?

No. Recall is one possible outcome at the end of a chain that runs through validation, assessment, aggregation, signal evaluation and benefit to risk assessment. Labelling changes, safety communications and additional risk minimisation measures are far more common outcomes.

Who can report an adverse event in Nigeria?

Healthcare professionals, patients and consumers can report, and reporting by Certificate of Registration Holders is a regulatory obligation. Reports are made on ADR forms, also called yellow forms or ICSR forms, available from NAFDAC state offices, the National Pharmacovigilance Centre in Abuja and the zonal pharmacovigilance centres, or through NAFDAC's online ADR e-reporting form and the Med Safety application.

How does NAFDAC use adverse event reports?

Reports are used to build a picture of how products behave in Nigerian patients, to detect signals that clinical trials could not have identified, to support benefit to risk evaluation, to inform safety communication, and to contribute Nigerian data to global safety surveillance through the WHO Programme for International Drug Monitoring.

Regulatory sources and references

National Agency for Food and Drug Administration and Control. NAFDAC Good Pharmacovigilance Practice Guidelines (Doc. Ref. PV/PMS-GDL-017-01), effective 21 January 2021. https://www.nafdac.gov.ng/wp-content/uploads/Files/Resources/Guidelines/PVG_GUIDELINES/NAFDAC-Guidelines-on-Good-Pharmacovigilance-2021.pdf
National Agency for Food and Drug Administration and Control. Handling Adverse Drug Reactions (ADRs): how to obtain and submit an ADR form.
National Agency for Food and Drug Administration and Control. Nigerian Guidelines for Detecting and Reporting of Adverse Reactions for Pharmaceutical Products and Medical Devices.
National Agency for Food and Drug Administration and Control. Pharmacovigilance and Post Market Surveillance Guidelines index.
National Agency for Food and Drug Administration and Control. Guidelines for Post Marketing Surveillance in Nigeria.
World Health Organization. WHO Collaborating Centres for pharmacovigilance and the Uppsala Monitoring Centre.
Uppsala Monitoring Centre. What we do: operating the WHO Programme for International Drug Monitoring.
Elemuwa UG, Bitrus F, Oreagba IA, Osakwe AI, Abiodun AS, Onu K, et al. Trends in Adverse Event Reporting Before and After the Introduction of the Med Safety App in Nigeria. Pharmaceutical Medicine, 2024. PubMed record 38705932
World Health Organization. Egypt and Nigeria medicines regulators achieve high maturity level in WHO classification, 30 March 2022.
CASRAI Standards. Serious Adverse Events (SAE), 5 September 2026.
MedNova Lifesciences. Pharmacovigilance services, Nigeria and Africa. mednovalife.com/pv.html
MedNova Lifesciences. Regulatory affairs services, Nigeria and Africa. mednovalife.com/regulatory.html