Why Adverse Drug Reactions Go Unreported in Hospital Pharmacies

Ask pharmacy staff in a hospital whether reporting adverse drug reactions matters, and nearly everyone says yes. Ask how many reports they filed last year, and the answers get much shorter.

Tanzanian studies show the same pattern. At Kilimanjaro Christian Medical Centre (KCMC), a 2016 survey of 63 health-care providers in HIV, dermatology and infectious disease clinics found that all of them agreed reporting was necessary. Yet 32 (50.8%) had never filled in a reporting form, 42.9% rarely did, and only four (6.3%) always did. A later multicentre survey of 380 health professionals in five regions, working in hospitals, pharmacies, health centres, dispensaries and accredited drug dispensing outlets (ADDOs), found that 86.8% held favourable attitudes towards reporting, while 22.9% had actively reported to the national regulator.

This article looks at that gap. It explains what a suspected reaction is and how a hospital pharmacist can judge whether a medicine is the likely cause. It then follows a report from the ward to the regulator, examines where reports are lost, and describes what has raised reporting in Tanzanian hospitals. Community pharmacies and ADDOs get a shorter section, and six common myths are checked at the end.

Why reports from practice matter

A medicine reaches the market after trials with limited numbers of patients, followed for limited periods under controlled conditions. A review in a Malaysian university journal notes that these patients are not representative of everyone who will later use the product, and that a reaction affecting about one user in 2,000 can be missed before registration. Long-term effects, and use in pregnancy, older age or alongside several other medicines, are also poorly covered.

The same review traces organised pharmacovigilance to the thalidomide disaster of the early 1960s and a WHO call in 1971 for national monitoring centres. For a hospital pharmacy the practical point is simple. Rare and delayed reactions are found in routine care, among patients who return with a rash, stop a long-term medicine because of a symptom, or ask whether a new complaint could be linked to something they were given last week.

What counts as an adverse drug reaction

The World Health Organization (WHO) defines an adverse drug reaction (ADR) as a harmful and unintended response to a medicine at doses normally used for prevention, diagnosis or treatment. The Uppsala Monitoring Centre (UMC), the WHO collaborating centre for international drug monitoring, points out that the term is often used loosely for all kinds of adverse events, many of which have not been assessed for cause.

Three terms are worth keeping apart, because confusing them is a documented reason reporting suffers. The authors of a 2023 study from the southern highlands note that providers sometimes struggle to tell ADRs, medication errors and side effects apart.

• An adverse drug reaction is harm from the medicine itself, used as intended.
• A medication error is harm, or the risk of harm, arising from how a medicine was prescribed, dispensed, administered or monitored.
• An adverse drug event is the wider term. A Tanzanian study of reporting describes it as covering both harm from the nature of a medication and harm from medication errors.

The distinction changes what a pharmacy department does next. A reaction goes to the national pharmacovigilance centre. An error also needs a local review of the process that allowed it, whatever else is reported.

Is the medicine really to blame?

Hospital patients often take several medicines at once, alongside an illness, an infection or a recent procedure. A new rash, a drop in blood count or a change in mental state could come from the disease, another medicine, an interaction, a herbal product, a missed dose or a poor-quality product.

WHO guidance on causality is frank about the difficulty. It notes that most case reports concern suspected reactions, that reactions are rarely specific to one drug, that diagnostic tests are usually absent, and that re-exposing a patient to confirm a reaction is rarely ethically justified. A pharmacist therefore cannot expect certainty before reporting.

A structured set of questions helps a pharmacist document a reasoned suspicion:

1. When did the event begin in relation to the first dose, or a change in dose?
2. Did it ease after the medicine was withdrawn or reduced? That decision belongs to the prescriber, and the pharmacist’s role is to see that the outcome is recorded.
3. Could the underlying disease, another medicine, an interaction or a herbal product explain it?
4. Is the reaction described in the product information or the national treatment guideline?
5. Does the batch, packaging or appearance of the product raise a quality concern?

These questions mirror what standardised causality systems weigh. The WHO-UMC system, used by pharmacovigilance centres, grades cases from “certain” through “probable”, “possible” and “unlikely” to “conditional” and “unassessable”. UMC’s own materials say such a system can reduce disagreement between assessors, but it cannot turn uncertainty into certainty.

A report therefore records a reasoned suspicion with enough detail to be assessed. The formal assessment happens at the pharmacovigilance centre, and the clinical decision to stop, switch or continue a medicine stays with the prescriber.

Where reports are lost between the ward and the regulator

Studies from Tanzanian hospitals point to several recurring reasons.

Time, effort and uncertainty about the process

At KCMC, providers named lack of motivation, uncertainty about reporting procedures, lack of time, unavailable reporting forms and ignorance as the main factors. In the Mbeya study, which interviewed doctors, nurses and pharmacists at a zonal and a regional referral hospital, participants were familiar with both paper and online reporting platforms. They still described reporting as laborious, a subjective burden, and not necessary for every ADR, and that limited their participation.

Training and forms

At KCMC, only 32 of 63 providers had received pharmacovigilance training, and the authors report that training had a positive influence on reporting. The 2025 five-region survey reached a similar conclusion. Pharmacovigilance training and the availability of reporting forms were significant factors in reporting practice, and 65.8% of respondents scored low on knowledge of pharmacovigilance. A study of nurses in Dar es Salaam published in 2018 reported that 80.8% of respondents in public hospitals said they had no access to ADR reporting forms. A 2020 master’s dissertation at the University of Dar es Salaam, covering regional referral hospitals in Dar es Salaam, found that 87% of health workers had a positive attitude towards reporting but that knowledge of it was inadequate. Knowledge of ADRs was recorded in 45.3% of doctors, 30.6% of nurses and 45.5% of pharmacists. This is a single-hospital master’s dissertation, not a peer-reviewed paper, so it supports the case for training rather than any wider claim.

Fear, feedback and the sense that one report changes nothing

The Mbeya authors list reasons for under-reporting found in the wider literature: complacency, fear of legal action, guilt about causing harm, lack of awareness and insecurity about reporting a suspicion. A systematic review of Ethiopian studies adds concern about extra work, a belief that one report makes no difference, unavailable forms and lack of feedback from the regulator. A scoping review of sub-Saharan Africa sorts the challenges into provider-related, work-related, tools-related and national pharmacovigilance-related groups.

Feedback has been recognised locally. Authors writing about Tanzania’s reporting programme say the Tanzania Medicines and Medical Devices Authority (TMDA) has placed more emphasis on prompt feedback to reporters.

Where the hospital pharmacy sits

Reactions happen on wards, in outpatient clinics and at home after discharge. The pharmacy learns of them only through dispensing, counselling, ward rounds, medication histories and questions from nursing staff. This is an observation from how hospitals work rather than a research finding. It means a pharmacist who is never asked about reactions has no way of knowing they occurred.

Pharmacists have some advantages once a suspected reaction is known. A systematic review of Ethiopian studies found pharmacists were more likely to report ADRs than other health professionals, and a Ghanaian doctoral thesis concluded that enhancing the role of pharmacists may help improve reporting. Pharmacists also tend to hold the details reports often lack. The 2025 Tanzanian survey found that submitted reports lacked important information for causality assessment and signal identification. Product names, batch numbers, dates and the full list of concurrent medicines are exactly what a pharmacy can supply.

What happens after a report is filed

The Mbeya study describes two routes into the national system. A patient or consumer can report directly to TMDA, or tell a health professional who then reports. Health professionals can also initiate a report to TMDA. TMDA compiles the reports and sends them to the Uppsala Monitoring Centre.

TMDA’s own page on paper-based submission describes the ADR Reporting Yellow Form (revised 2021). Each patient needs a separate form. The form asks for patient details, a description of the reaction with its date of onset, the suspected medicine (name, dose, route, start and stop dates, reason for use), treatment given, other relevant history, the outcome, and the reporter’s name, date, signature and address. TMDA says forms are available from its headquarters, Zonal Drug Information Centres, Regional Medical Officers or Regional Pharmacists, and health facilities. The same page lists other routes: the online Safety and Quality Reporting Tool, a text-message (USSD) service introduced in 2018, and a toll-free telephone line. TMDA’s adverse drug reaction page adds an email address for ADR reports, an Android app and a separate green form for consumers, alongside the yellow form for health-care providers. It names specialists, doctors, dentists, pharmacists and nurses as providers who can report, and says affected consumers should report to their health professionals or to the zonal Drug Information Centres. Confirm the current addresses, codes and numbers on TMDA’s site before putting them on a ward notice.

Tanzania’s system has a long history. TMDA’s page dates the paper system to 1987. A Tanzanian journal article places the country’s membership of the WHO international drug monitoring programme in 1993, and an EDCTP report says the national system, introduced in 1989, relies on spontaneous, or passive, reporting. The Mbeya authors list the Ministry of Health’s strategies through TMDA as pharmacovigilance regulations in 2018, guidelines in 2020 and the appointment of a pharmacovigilance focal person.

For a pharmacist asking whether a single report matters, the UMC definition of a safety signal is the useful reference. A signal is information on a new or known side effect that may be caused by a medicine, and it is typically generated from more than a single report. Once a signal is detected, the relationship is evaluated through causality assessment, and a credible association is communicated to members of the WHO programme. One report is one piece of a pattern, and the pattern only forms if the pieces arrive.

What has raised reporting in Tanzanian hospitals

The clearest Tanzanian evidence comes from a programme called structured stimulated spontaneous safety monitoring (SSSSM). It was introduced in seven tertiary hospitals, combining awareness and training for health professionals with a more structured way of collecting reports. Researchers compared 18 months before the programme (July 2017 to December 2018) with 18 months after it (January 2019 to June 2020).

The numbers changed sharply. Of 16,557 reports, 98.6% (16,332) came after the intervention. Reports rose from 20 to 11,637 in Dar es Salaam, from 49 to 316 in Kilimanjaro and from 17 to 77 in Mbeya. The national reporting ratio rose from 2 reports per million inhabitants in 2018 to 85 in 2019, and the authors found the programme useful for detecting signals across all types of medicines.

Three cautions apply. The study was quasi-experimental, with one group compared before and after, so other changes during the period could have contributed. The figures count reports, and a higher count does not show that each report was complete. And the 2025 survey, which found reports missing key information, suggests quality still needs attention. Training also appears elsewhere. A 2025 announcement from Muhimbili University of Health and Allied Sciences (MUHAS) advertised a pharmacovigilance course with faculty from MUHAS and TMDA.

A reporting routine for a hospital pharmacy

The steps below are editorial suggestions drawn from the barriers described above. They are not official requirements, and each facility should align them with current TMDA guidance and its own policies.

1. Look after the patient first. Pharmacy staff do not diagnose or stop prescribed treatment on their own. A patient with a worrying reaction needs assessment by the prescriber, and an urgent reaction needs urgent referral. Reporting follows, and does not replace, that step.
2. Put the reporting route within reach. Keep copies of the current yellow form and instructions for the online and text-message routes at dispensing points, on wards and at the drug information desk, since unavailable forms are a documented barrier. TMDA lists Zonal Drug Information Centres and Regional Pharmacists among the places to obtain forms.
3. Name a pharmacovigilance contact in the pharmacy department. This person helps colleagues complete reports, checks that they are sent and reports back on what happens.
4. Ask the question routinely. Add a prompt about new symptoms since starting or changing a medicine to counselling, medication histories and ward-round checklists, so reactions reach the pharmacy without relying on someone remembering to mention them.
5. Capture the essentials at the time. Record the suspected medicine, product, batch number, dose and dates as documented in the patient’s file, a description of the event with its onset and outcome, other medicines including herbal products, and the reporter’s details. Keep patient identifiers to what the form requires, and keep the case out of social media, group chats and casual conversation.
6. Keep errors on a separate track. Report suspected reactions to the national centre, and review medication errors through the facility’s incident process.
7. Tell the patient what happens next. Patients who understand why a report is made are more likely to mention problems later, and a Mbeya patient survey (see below) found most patients did not know why reporting matters.
8. Close the loop. Log reports, discuss anonymised cases at department or drug and therapeutics committee meetings, and share any feedback from TMDA when it arrives.
9. Train and refresh. Include pharmacovigilance in induction for new staff and interns, and use available courses.

Pharmacists, pharmaceutical technicians, pharmaceutical assistants and ADDO dispensers work under different scopes of practice. This article does not set out what the law requires of each cadre. Readers should check the current TMDA pharmacovigilance regulations and the Pharmacy Council of Tanzania’s guidance for the duties that apply to their own role and premises.

Community pharmacies and ADDOs

The same problem exists outside hospitals, with different features. A 2011 study of community pharmacy dispensers in Dar es Salaam, cited in the national press, recommended government intervention to address weak reporting. The 2025 five-region survey included pharmacies and ADDOs, though its abstract does not separate results by setting.

A community dispenser has no ward round to prompt reports. A reaction usually reaches the counter as a complaint from a returning customer, often after a purchase made without a prescription. The national system also accepts patient reports. A Tanzanian newspaper health column describes a Swahili patient reporting form and patient alert cards, and WHO guidance says consumer reports should complement rather than replace reports from health-care professionals. A survey of 792 adults with chronic conditions at Mbeya Zonal Referral Hospital found that 21.6% had experienced an ADR and 14.1% knew that an ADR is an unexpected harm after taking a medicine. Most (88.9%) preferred to report to a health-care provider, and the authors recommended awareness campaigns. That makes the person at the counter or the hospital outpatient pharmacy the likeliest route for a patient report. Dispensers can ask repeat customers about earlier reactions, send people with serious symptoms to a health facility, and help patients report.

Six myths about reporting, checked

Key points

• Support for reporting is high among Tanzanian health professionals, but actual reporting is low, and the gap is the problem to solve.
• A report records a reasoned suspicion. The pharmacovigilance centre assesses causality, and the prescriber decides about treatment.
• Documented barriers include time, uncertainty about the process, missing forms, limited training and little feedback.
• Training and structured reporting raised report numbers in seven tertiary hospitals, though report quality still needs work.
• A hospital pharmacy can raise reporting by making forms available, naming a contact person, asking about reactions routinely and closing the feedback loop.

This article is for educational and informational purposes and is not individual medical advice. It does not replace professional consultation. Patients should not stop or change prescribed medicines without advice from a qualified health professional. Reporting requirements and tools may change, so check current TMDA guidance.