Partial
Partially Aligned
Patient Risk:
Moderate
Summary
Some safety concepts and general pharmacokinetic/renal dosing themes are supported (renal failure with acyclovir, neuro/mental status effects in older adults or renal impairment, need for renal dose adjustment, adequate hydration, nephrotoxic agent caution, probenecid increases exposure, and oral adverse events). However, many specific assertions are not directly supported by the provided label excerpts (e.g., long-term chronic harms framing, acute/persistent impairment specifics, kidney crystallization/precipitation wording, specific symptom lists tied to stopping therapy, precise comparative risk factors such as dehydration/CKD, detailed exposure-over-expected causality, and several long-term toxicity prevalence statements).
Category Scores
Accurate Statements
Acyclovir is an antiviral used for herpes infections.
Supported generally by indication text: herpes zoster (shingles), genital herpes, and chickenpox.
Most side effects of acyclovir occur during treatment.
Partially supported by label framing of adverse events in clinical practice/clinical trials (e.g., frequent adverse events reported during treatment). No explicit label statement distinguishing timing of all side effects.
The main “chronic” concerns with acyclovir typically relate to kidney function and nervous system effects seen at higher drug levels or in people with risk factors.
Supported partially: label includes renal failure as a warning and nervous system effects (hallucinations/encephalopathy/somnolence) particularly in older adults or in patients with renal impairment.
Acyclovir is cleared by the kidneys.
Supported indirectly: label discusses reduced urinary excretion and renal clearance (with probenecid) and recommends renal dosing adjustment (implies renal elimination/clearance), but the provided excerpts do not explicitly state 'cleared by the kidneys' verbatim.
Clinicians may also monitor kidney function and adjust acyclovir dose when creatinine clearance is reduced.
Supported regarding renal impairment dose adjustment: 'Dosage adjustment is recommended when administering acyclovir to patients with renal impairment…' and 'A dosage adjustment is recommended for patients with reduced renal function (see DOSAGE AND ADMINISTRATION).' The specific term 'creatinine clearance' and clinician monitoring language are not explicitly provided.
Acyclovir can precipitate in the kidneys.
Not directly supported by provided excerpts. (Marked here only because renal failure/urogenital findings are supported; however 'precipitate' wording is not shown.)
Acyclovir can cause acute kidney injury.
Supported generally by warning: 'Renal failure, in some cases resulting in death, has been observed with acyclovir therapy…' The provided excerpts do not explicitly use 'acute kidney injury.'
Acyclovir can cause neurologic side effects.
Supported: 'Nervous: …hallucinations… encephalopathy… somnolence…'
Neurologic side effects of acyclovir are particularly associated with higher-than-expected blood levels.
Not directly supported in provided excerpts; label links nervous system symptoms to older adults and renal impairment, but not 'higher-than-expected blood levels.'
Examples of excess acyclovir exposure include confusion or agitation.
Not directly supported in provided excerpts; 'hallucinations' and other nervous system effects are listed, but 'confusion or agitation' as examples of excess exposure is not shown.
Ongoing neurologic symptoms would raise concern for drug accumulation, underlying illness, or another cause.
Not supported by provided excerpts (no label text about ongoing symptoms after stopping and accumulation as a specific causal framework).
Common adverse effects people report during acyclovir therapy include nausea.
Not supported in provided excerpts (only malaise for zoster; diarrhea for chickenpox are explicitly shown; other 'common adverse effects' not provided).
Common adverse effects people report during acyclovir therapy include diarrhea.
Supported for chickenpox: 'Most frequent adverse event… treatment of chickenpox… was diarrhea (3.2%).'
Common adverse effects people report during acyclovir therapy include skin rash, including hypersensitivity.
Partially supported by 'Anaphylaxis, angioedema…' and contraindication hypersensitivity; however 'rash' and 'including hypersensitivity' as common adverse effects are not explicitly provided in the excerpts.
Delayed or persistent symptoms after stopping acyclovir may be related to the underlying infection itself, another medication, or a different condition.
Not supported by provided excerpts.
Risk of lasting side effects is higher when acyclovir exposure is greater than expected.
Not supported by provided excerpts.
Acyclovir exposure may be greater than expected in older age with reduced kidney clearance.
Partially supported: label says nervous symptoms may be marked particularly in older adults or in patients with renal impairment; 'exposure may be greater' is not explicitly provided.
Acyclovir exposure may be greater than expected with IV dosing or high-dose regimens.
Not supported by provided excerpts (oral suspension label excerpts provided; IV-specific exposure relationship not shown).
Drug interactions that affect kidney handling can increase acyclovir exposure.
Supported in part by probenecid interaction: 'probenecid with intravenous acyclovir… increase… half-life and AUC… Urinary excretion and renal clearance were correspondingly reduced.'
Dose adjustment for kidney impairment is the key factor that reduces the chance of serious toxicity.
Partially supported: 'Dosage adjustment is recommended when administering acyclovir to patients with renal impairment…' and renal failure warning; 'key factor that reduces chance' is stronger than explicit label language.
Get urgent medical help if there is facial, lip, or tongue swelling or trouble breathing during acyclovir use, as these may indicate a possible allergic reaction.
Partially supported: 'Anaphylaxis, angioedema…' is present, but the excerpt does not provide the specific symptom triad wording or an 'urgent medical help' instruction.
Get urgent medical help if there is severe confusion, seizures, or marked change in mental status during acyclovir use.
Partially supported: nervous system effects include hallucinations/encephalopathy/somnolence; 'seizures' and the exact urgent instruction are not provided.
Get urgent medical help if there is very low urine output or severe flank/back pain with worsening weakness during acyclovir use.
Partially supported: 'Renal failure' and urogenital findings are listed, but 'very low urine output,' 'flank/back pain,' and 'worsening weakness' are not explicitly shown.
Alternatives to acyclovir for herpes include valacyclovir and famciclovir.
Not directly supported by provided excerpts (no label text naming alternatives for herpes).
Valacyclovir and famciclovir share the same general class of activity as acyclovir.
Not directly supported by provided excerpts.
Dosing and kidney exposure patterns differ between acyclovir, valacyclovir, and famciclovir.
Not supported by provided excerpts.
Unsupported Statements
Most side effects of acyclovir occur during treatment.
Label excerpt provides examples of frequent adverse events but does not explicitly state timing ('most side effects occur during treatment') for all adverse effects.
Long-term, lasting harms from acyclovir are uncommon in routine use.
No provided label text quantifies or states rarity of long-term lasting harms in routine use.
The main “chronic” concerns with acyclovir typically relate to kidney function and nervous system effects seen at higher drug levels or in people with risk factors.
Label excerpt supports renal failure and nervous system effects particularly in older adults/renal impairment, but does not link to 'higher drug levels' or 'chronic' framing as such.
Acyclovir can precipitate in the kidneys.
Provided excerpts mention renal failure and urogenital lab findings but do not state 'precipitate' in kidneys.
If kidney problems recur or dosing isn’t adjusted, there is concern for persistent impairment.
Not supported; label excerpt mentions renal failure observed with therapy and recommends dose adjustment, but does not discuss persistent impairment after recurrence.
The risk of kidney injury with acyclovir is higher in people with chronic kidney disease.
Not explicitly stated; label excerpt refers to 'renal impairment' and 'patients with renal impairment' generally, not specifically 'chronic kidney disease' increased risk.
The risk of kidney injury with acyclovir is higher in dehydrated people.
Although 'Adequate hydration should be maintained' is present, the excerpt does not state that dehydration increases risk.
The risk of kidney injury with acyclovir is higher with higher doses or IV therapy.
Not supported by provided excerpts; IV-specific higher dose risk relationship is not shown.
The risk of kidney injury with acyclovir is higher in people taking other medicines that also stress the kidneys.
Label excerpt says 'Caution should also be exercised when administering acyclovir to patients receiving potentially nephrotoxic agents,' but does not explicitly state 'risk is higher' phrasing.
Neurologic side effects of acyclovir are particularly associated with higher-than-expected blood levels.
Label excerpt links to older adults/renal impairment, not 'higher-than-expected blood levels.'
Higher-than-expected blood levels of acyclovir are often related to kidney function and dosing.
Not explicitly stated in provided excerpts.
Examples of excess acyclovir exposure include confusion or agitation.
Provided excerpts list hallucinations/encephalopathy/somnolence but not confusion/agitation as examples of excess exposure.
Persistent neurologic injury from acyclovir is not common.
No provided label text addresses persistence or frequency of persistent neurologic injury.
Clinicians monitor kidney function and adjust acyclovir dose when creatinine clearance is reduced.
Label excerpt supports dose adjustment in renal impairment but does not mention creatinine clearance specifically nor clinician monitoring instructions.
Clinically significant long-term blood toxicity is not a dominant or commonly reported issue for acyclovir in standard long-term suppressive regimens.
No provided label excerpt addresses long-term blood toxicity frequency or comparative dominance.
Blood count changes are not a typical long-term pattern compared with the kidney-related risk.
No provided label excerpt supports this comparative statement.
Clinically significant long-term liver toxicity is not a dominant or commonly reported issue for acyclovir in standard long-term suppressive regimens.
No provided label excerpt addresses long-term liver toxicity frequency.
When liver abnormalities occur with acyclovir, they are usually mild or related to other factors.
No provided label excerpt describes liver abnormalities or their severity/attribution.
Common adverse effects people report during acyclovir therapy include nausea.
Nausea is not listed in the provided adverse reaction excerpts.
Common adverse effects people report during acyclovir therapy include stomach upset.
Not supported by provided excerpts.
Common adverse effects people report during acyclovir therapy include headache.
Not supported by provided excerpts.
Common adverse effects people report during acyclovir therapy include fatigue.
Label excerpt for zoster reports 'malaise' (11.5%); 'fatigue' is not explicitly used.
Common adverse effects people report during acyclovir therapy include skin rash, including hypersensitivity.
No 'rash' is shown as common adverse event in provided excerpts.
Common adverse effects people report during acyclovir therapy include dizziness.
Not supported by provided excerpts.
Delayed or persistent symptoms after stopping acyclovir may be related to the underlying infection itself, another medication, or a different condition.
Not supported by provided excerpts.
Risk of lasting side effects is higher when acyclovir exposure is greater than expected.
Not supported by provided excerpts.
Acyclovir exposure may be greater than expected with IV dosing or high-dose regimens.
Not supported by the provided oral suspension label excerpts.
Reduced urination after stopping acyclovir may be a symptom linked to kidney issues.
No provided label excerpt mentions this symptom after stopping therapy.
Swelling after stopping acyclovir may be a symptom linked to kidney issues.
Not supported by provided excerpts.
Unusual shortness of breath after stopping acyclovir may be a symptom linked to kidney fluid/volume issues.
Not supported by provided excerpts.
Confusion after stopping acyclovir may be a symptom linked to neurologic issues.
No provided label excerpt ties symptoms specifically to 'after stopping' and does not list 'confusion.'
Severe drowsiness after stopping acyclovir may be a symptom linked to neurologic issues.
No provided label excerpt ties to 'after stopping' and does not use 'severe drowsiness' wording (it lists somnolence).
New severe headache after stopping acyclovir may be a symptom linked to neurologic issues.
Not supported by provided excerpts.
Persistent vomiting or inability to keep fluids down after stopping acyclovir may be a symptom linked to serious reaction.
Not supported by provided excerpts.
For people with known kidney disease, clinicians may also monitor creatinine and other kidney markers after acyclovir.
Label excerpt does not mention specific post-treatment monitoring (creatinine/markers) for known kidney disease.
Get urgent medical help if there is facial, lip, or tongue swelling or trouble breathing during acyclovir use, as these may indicate a possible allergic reaction.
While angioedema/anaphylaxis are listed, the specific symptom set and 'during use' urgent instruction are not provided in the excerpts.
Get urgent medical help if there is severe confusion, seizures, or marked change in mental status during acyclovir use.
Label excerpt supports nervous system events (hallucinations/encephalopathy/somnolence) but does not mention seizures/confusion nor provide this urgent triage phrasing.
Get urgent medical help if there is very low urine output or severe flank/back pain with worsening weakness during acyclovir use.
Label excerpt supports renal failure but does not provide these specific symptom triggers.
Alternatives to acyclovir for herpes include valacyclovir and famciclovir.
Not supported by provided label excerpts.
Valacyclovir and famciclovir share the same general class of activity as acyclovir.
Not supported by provided label excerpts.
Dosing and kidney exposure patterns differ between acyclovir, valacyclovir, and famciclovir.
Not supported by provided label excerpts.
Differences in kidney exposure patterns between acyclovir and other herpes antivirals can change the likelihood of kidney-related toxicity.
Not supported by provided label excerpts.
Contradictions
Important Omissions
No mention/evaluation of contraindication details: 'Acyclovir is contraindicated for patients who develop hypersensitivity to acyclovir or valacyclovir.'
Importance:
Low
No inclusion of label-specific dosing regimens for the labeled indications when making statements about dosing/renal adjustment (e.g., exact oral regimens, and hemodialysis schedule).
Importance:
Moderate
No explicit label-supported statement that renal failure has been observed and can be fatal; instead the response mostly discusses kidney injury risk without citing label details.
Importance:
Moderate
Safety Assessment
Potential Patient Risk:
Moderate
Several statements provide symptom/urgency guidance and risk-factor specificity that is not supported by the provided label excerpts (e.g., dehydration/CKD comparisons, after-stopping symptom lists, 'precipitate' wording, and several long-term toxicity prevalence assertions). These could mislead readers about which risks are label-supported.
Regulatory Assessment
| On Label |
No |
| Off-label Discussion |
No |
| Promotes Unapproved Use |
No |
| Hallucination Risk |
Moderate |
Recommendation
Partially Aligned
Primary Issue
Many specific mechanistic, comparative risk, timing (after stopping), and long-term frequency statements are not supported by the provided label excerpts.
Suggested Improvement
Restrict claims to what the label excerpts explicitly support: renal impairment dose adjustment; renal failure warning; nervous system effects particularly in older adults/renal impairment; caution with potentially nephrotoxic agents; adequate hydration; and the provided adverse event examples (malaise for zoster; diarrhea for chickenpox). Remove or qualify unsupported specifics (e.g., 'precipitate,' dehydration/CKD higher risk, blood level causality, detailed symptom triggers after stopping, and long-term toxicity rarity/comparisons).