HONG KONG – For five years in a row, China has seen the number of adverse effects from pharmaceuticals rise, but while the numbers are negative at first blush they do point to an improved and much broader monitoring network that has increased the country's pharmacovigilance capability.

The CFDA published last week its adverse event monitoring report for 2014, in which it pointed out that its monitoring network has spread further afield.

"In 2014, there were more than 240,000 medical institutions, pharmaceutical manufacturers and sellers registered as a part of the monitoring network," said the CFDA. "This indicates that our ability to discover and collect information on adverse drug reactions has been increased."

The CFDA received 1.328 million reports of adverse events in 2014, a 0.8 percent increase from 2013. Among the reported cases, 340,000 were new adverse reaction or severe cases. Between 1999 and 2014, there have been some 7.9 million adverse reactions.

"New and severe cases are the key to monitoring adverse drug reactions," said the CFDA. "The proportion of these cases, especially severe cases, is an important indicator of the quality and [usability] of the monitoring report."

The number of adverse drug reactions per 1 million people also rose 0.8 percent to 991 in 2014. That is a key metric for the regulator. The CFDA's report shows that adverse reactions tend to peak between October and December, spiking in November, but the differences from month to month are getting smaller.

Doctors and pharmacist nurses at medical institutions reported the majority of cases, about 82 percent. Drug sellers are the second major source of reaction reports while individuals also reported 0.4 percent of cases.

Most of the adverse reactions reported were associated with chemical drugs or traditional Chinese medicine (TCM), with biologics accounting for just 1.5 percent of cases.

While chemicals and TCM are more likely to cause problems to the skin, gastrointestinal system and general health, biologics are more likely to have an adverse impact on the skin, the whole body and respiratory system.

Another factor the CFDA took into consideration was the method of drug distribution. Intravenous injections caused 2.1 percent more adverse reactions than in 2013, while drugs taken orally were associated with fewer incidents.

Roughly 520,000 adverse reactions were associated with drugs on the country's Essential Drug List in 2014, with as many as 29,000 reported as severe. Some 443,300 cases were linked to some 317 chemical and biological drugs on the list and accounted for 83 percent of the cases linked to drugs on the list. The current Essential Drugs List was released in 2012 and includes three categories of drugs: chemical and biological, TCM and TCM decoctions.

The top drug categories from the list that caused adverse reactions were antimicrobial drugs, cardiovascular agents, cancer drugs, digestive system agents and analgesia or anti-inflammatory drugs. Antimicrobial drugs including levofloxacin, ceftriaxone, cefuroxime, ceftazidime and penicillin were most frequently named.

The reactions caused by those drugs range from damage to the gastrointestinal system, the skin, central and peripheral nervous system to general and respirational damage. Patients reported a range of symptoms such as rash, nausea, headaches, allergy, diarrhea, chest pain, fever and fatigue.

Anti-infectious drugs took up 38 percent of the total adverse reaction reports in 2014, roughly a half-million cases and 2 percent less than in 2013. Still, those drugs were the top source of adverse drug reactions. Antibiotics are on the top of the list of anti-infectious drugs that are causing problems.

The report noted that a key concern for the CFDA is adverse reactions in children. Part of the concern stems from the limited pre-market safety data in medicines for children. The CFDA found the risk of adverse reaction to anti-infectious drugs increases when the users of the drugs are young children.

At the same time, seniors taking more than five kinds of drugs are more likely to suffer from adverse reactions due to the aging of their tissues and organs.

Adverse reaction also can be caused by misuse of drugs or by fake drugs. The latter is a particular concern. BMI Research forecasts that online retailing will emerge as a key sales channel for health care products in China, which could lead to significant risks.

"A key risk of the sector's growth will be the proliferation of fake drugs being sold online, posing a significant threat to public health," said BMI in a report.