DISCUSSION
The prevalence of prescribing issues—PIMs/PIP, PPOs, and drug
interactions—reached almost 90% and is a cause for concern among
older HIV-infected patients. We identified several differences according
to the criteria applied to identify these issues.
Older PLWH are often affected by comorbidities and polypharmacy
[24-26] and can therefore be considered an at-risk population for
prescribing issues and, consequently, for ADRs. However, to our
knowledge, only 3 published studies have assessed this issue in PLWH
[27-29]. Our results from the Over50 cohort show that almost all of
the patients aged ≥65 years presented at least 1 prescribing issue; half
had received at least 1 medication that had to be stopped (PIM by Beers
or PIP by STOP). This high rate is similar to that detected in San
Francisco in the USA [27,28]. One study detected at least 1 PIM in
52% of patients in a group of 89 PLWH based on the Beers criteria
[27]. A similar prevalence was seen in a second study [28],
which included a larger sample (211 patients) and compared both the
STOPP/START and the Beers criteria, as did we. Of note, prescribing
issues were more prevalent when the Beers criteria were applied than
when the STOPP criteria were applied (63% vs 54%, respectively). Since
the population studied was American, this result was expected. Data from
the Swiss cohort [29] show that the prevalence of PIMs in 122
patients aged > 65 years based only on the Beer
criteria was lower than that observed among our patients based on the
Beers and the STOPP criteria, around one third of the population
compared with a half, respectively. More than half of the medications
for which the Beers criteria apply are not available in Spain, and this
could be one of the reasons why prescribing issues in Europe are more
frequently detected with the STOPP criteria than with the Beers criteria
[12]. In this sense, these data indicate that the STOPP/START
criteria are more appropriate than the Beers criteria for evaluation of
prescribing issues in a European population.
Benzodiazepines were the drugs most frequently involved with PIMs in our
and the Swiss cohort [29]. These medications are widely prescribed
to the patients we attend, and those with long-term effects should be
avoided in elderly patients at risk of falls and in those receiving
other drugs that act on the central nervous system. In the American
population, however, testosterone was the most frequently involved drug,
probably owing to more frequent prescription of this drug among older
American PLWH. In contrast, vaccines and vitamin D supplements were the
recommended drugs least often prescribed. In line with national
guidelines, it is also necessary to recommend vaccines and vitamin D
supplements among older PLWH. Therefore, it is very important to
carefully and regularly check the concomitant treatment of elderly PLWH
at each medical visit, especially in cases involving multiple
comorbidities and polypharmacy where different prescribers are involved
[29-31]. This routine avoids unnecessary medications, adverse
events, and drug-drug interactions.
Finally, our results also illustrate the relevance of choosing the most
appropriate antiretroviral drug in elderly PLWH. As expected,
antiretroviral combinations including the booster cobicistat were more
frequently associated with drug-drug interactions. For that reason,
these combinations should be proactively monitored. Recent studies
support the antiviral efficacy and safety profile of ART combinations
without a booster and some dual regimens [32-35] in order to
decrease the risk of drug-drug interactions associated with boosters and
prescription errors, as well as the risk of ADRs. In fact, despite the
lack of formal recommendations on optimal therapy for older PLWH, cohort
data demonstrate that the presence of comorbidities and polypharmacy led
the physician to prescribe unusual ART combinations, mostly dual
regimens [36].
Our study is potentially limited by its small sample size and by the use
of the previous version of the Beers criteria (although the
modifications of the 2015 revision made little difference to our
results) [37] . However, the data resulting from our analysis are
solid and relevant and add to the scarce published data. In addition,
they highlight the need for changes in our routine practice.
In summary, prescribing issues were very prevalent among our older PLWH,
with the most frequent being PIMs/PIP that could lead to avoidable ADRs.
This high prevalence requires us to optimize treatment strategies by
implementing a multidisciplinary critical review of our treatment plan
as part of routine practice [30,38]. Concomitant medications should
be more carefully and regularly monitored, especially in patients with
multiple comorbidities and polypharmacy. Boosted antiretroviral
combinations in particular should be used with caution. Although no
standardized guidelines are available for PLWH, we consider the
STOPP/START criteria to be a useful tool for European populations, since
they seem to better detect prescribing issues, as they do in the general
population.