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Adverse Event of RISPERDAL CONSTA - Injection Site Pain or Reactions

Last Updated: 08/30/2023

Summary

  • In a 12-week study, the mean intensity of injection pain following gluteal administration reported by patients using a visual analog scale (0=no pain to 100=unbearably painful) decreased in all treatment groups from the first to the last injection. After the sixth injection, investigator ratings indicated that 1% of patients treated with 25 mg or 50 mg RISPERDAL CONSTA experienced redness, swelling, or induration at the injection site.1
  • In a separate study to observe local-site tolerability in which RISPERDAL CONSTA was administered into the deltoid muscle every 2 weeks over a period of 8 weeks, no patient discontinued treatment due to local injection site pain or reaction. Clinician ratings indicated that only mild redness, swelling, or induration at the injection site was observed in subjects treated with 37.5 mg or 50 mg RISPERDAL CONSTA at 2 hours after deltoid injection. All ratings returned to baseline at the predose assessment of the next injection 2 weeks later and no moderate or severe reactions were observed in any subject.1
  • Serious injection site reactions including abscess, cellulitis, cyst, hematoma, necrosis, nodule, and ulcer have been reported with RISPERDAL CONSTA during postmarketing surveillance. Isolated cases required surgical intervention.1
  • Additional blinded trials, open-label trials, retrospective reviews, case reports, and letters to the editor are available regarding injection site pain or reactions during treatment with RISPERDAL CONSTA and are summarized below.

PRODUCT LABELING

Please refer to the following section of the Full Prescribing Information which is relevant to your inquiry: ADVERSE REACTIONS.

GLUTEAL ADMINISTRATION TRIALS


Gluteal Administration Trials
Lead Author/Trial Design
Treatment
Injection Site Resultsa,b
Double-Blind Trials
Pandina (2011)2 conducted a 13-week, randomized, double-blind, double-dummy, active-controlled, parallel-group, multicenter study assessing non-inferiority of PALM to RLAI in adult patients with schizophrenia (n=1214, safety analysis set).
Following a ≤7-day screening, washout, and tolerability period, patients were randomized to receive 1 of 2 treatments for a 13-week, double-blind period:
PALM (n=606)
  • Deltoid injection of PALM 234 mg on day 1 followed by a 156 mg deltoid injection on day 8; thereafter, patients received flexibly dosed PALM injections on days 36 (78 or 156 mg) and 64 (78, 156, or 234 mg) in either the deltoid or gluteal muscle.
  • Oral supplementation with PBO was provided for days 1-28. Optional supplementation with PBO could be administered with each dose increase. -PBO injections were matched to RLAI on day 8 and every 2 weeks thereafter.

RLAI (n=608)
  • RLAI 25 mg on days 8 and 22, followed by 25 or 37.5 mg on days 36 and 50; thereafter, patients received flexible doses of 25, 37.5, or 50 mg on days 64 and 78, all in the gluteal muscle.
  • PBO injections matched those of PALM on days 1, 8, 36, and 64.
  • Oral supplementation was with flexible RIS (1-6 mg) for the first 28 days. Optional supplementation with RIS 1-2 mg could be administered with each dose increase.
  • Injection site pain was reported in 5.1% of patients receiving paliperidone palmitate and 0.8% of patients receiving RLAI.
  • The results of investigator assessments of the injection site were similar for both groups.
  • Highest mean VAS scores occurred on Day 1 of injections.
  • Additional post-hoc analyses have been referenced for your convenience.3, 4
Fu (2014)5 performed a post-hoc analysis of the  13-week, randomized, double-blind, double-dummy, multicenter study reported above (Pandina 2011)2 to compare the efficacy and tolerability of PALM and RLAI in patients recently diagnosed (≤5 years ago) with schizophrenia.
PALM (n=161)
  • Dosing listed above.

RLAI (n=173)
  • Dosing listed above.
  • During the 13-week study, injection site pain was reported in 7 (4.3%) patients receiving PALM and 1 (0.6%) patient receiving RLAI. (Relative risk 0.13, 95% CI 0.02-1.07).
  • None of the patients in this post-hoc analysis discontinued the trial due to injection site reactions.
Quiroz (2010)6 conducted a parallel-group, multicenter study including a 26-week open-label stabilization phase and a randomized, double-blind phase up to 24 months duration in patients with Bipolar disorder (n=303 randomized)
Open-label
RLAI 25-50 mg every 2 weeks
then
RLAI 25-50 mg every 2 weeks (n=154)
or
Placebo (n=149)
One patient on RLAI in the open-label stabilization phase and one patient on placebo in the double-blind phase reported injection site pain.
  • No other injection site adverse events (such as induration or swelling) were reported.
Chue (2005)7 conducted a 12-week, double-blind, double-dummy, randomized, non-inferiority study in patients with schizophrenia (n=640)
RLAI 25, 50, or 75 mg every 2 weeks (n=319)
or
RIS oral 2, 4 or 6 mg/day (n=321)
  • The VAS mean scores for pain at the injection site were 18-20 and ratings were similar after injections containing placebo and risperidone.
  • Investigators rated pain and swelling as mild or absent, and induration as absent in most patients in both groups. Redness at the injection site was reported in 3.7-6.8% of patients receiving RLAI.  The frequency of this reaction decreased by the third injection.
Kane (2003)8 conducted a 12-week, randomized, double-blind, placebo-controlled study in patients with schizophrenia (n=400)
RLAI 25, 50, or 75 mg every 2 weeks or
Placebo
Patient ratings of injection site pain
 
RLAI
 
PBO
25 mg
50 mg
75 mg
Mean VAS score at 1stinj
16.7 n=96
12.0 n=97
18.2 n=102
16.7 n=100
Mean VAS score at 6thinj
12.6 n=32
9.0 n=44
11.8 n=43
8.5 n=45
Investigator ratings of injection site pain and swelling
 
RLAI
 
PBO
25 mg
50 mg
75 mg
Pain after 6thinj -% rated as absent
90% n=31
80% n=45
81% n=43
84% n=45
Swelling after 6th inj -% rated as absent
100% n=31
100% n=45
100% n=43
100% n=45
Single-Blind Trials
Bai (2007)9Bai (2006)10 conducted a 48-week, rater-blinded, randomized, parallel-group study in stable hospitalized schizophrenia patients treated with oral risperidone for ≥3 months (n=50)
RLAI 25, 37.5, or 50 mg every 2 weeks based on previous RIS oral dose (n=25) (flexible dose)
Or
RIS oral dose maintained at the patient’s dose prior to study entry (mean=3.8 mg/day); dose could be increased (n=25)
VAS pain rating scores (patient rated; 0=no pain, 10=unbearable pain) averaged 3.4 to 4.1 over the first 12 weeks, and the mean score (±SD) was 2.9±3.0 after 48 weeks. These scores corresponded to mild pain.
Open-Label Trials
Suzuki (2012)11 conducted an open-label, flexible-dose, naturalistic study assessing the safety and efficacy of switching 48 older Japanese patients with schizophrenia from oral RIS (stable doses ≥6 months) to RLAI versus continued treated with oral RIS (n=17; mean age: 63.8 years).
Stratified RLAI Groups:
≥60 years (n=18; mean age: 64.6 years)
<60 years (n=13; mean age: 45.4 years)
RLAI initiated at 25 mg via gluteal injection every 2 weeks and increased after 8 weeks as needed to optimize dose.
  • Along with RLAI initiation, previous medications were continued, then reduced after 4 weeks and discontinued by 8 weeks.
  • Mild injection site pain occurred in 22.6% (n=7/31) of RLAI patients at first or second administration and subsequently resolved.
  • No swelling, redness or induration was observed.
Rosenheck (2011)12 conducted a randomized, study examining risk of hospitalization following treatment with RLAI vs psychiatrist choice of oral antipsychotics in 369 unstable patients diagnosed with schizophrenia/ schizoaffective disorder
RLAI 25 mg every 2 weeks with dose titration every 4 weeks in 12.5 increments up to a maximum dose of 50 mg; oral antipsychotics were continued for at least 3 weeks and then reduced and discontinued.
Or
Psychiatrist's choice of an oral antipsychotic.
RLAI patients (n=85) reported more administration site conditions (injection-related pain or induration) and general disorders than the oral treatment group (n=63); P=0.03
Ruan (2011)13 conducted a 24-week, open-label trial in early onset/stable schizophrenia in 31 adolescent Chinese patients (mean age: 15.9 years; 41.9% male).
RLAI was initiated at 25 or 37.5 mg IM (gluteal) every 2 weeks based upon pre-study medication (4-week run in period with risperidone or olanzapine). Incremental titrations (12.5 mg) to a maximum dose of: 50 mg occurred at scheduled visits following at least 4 weeks of treatment with each dose.  
Self-ratings of local injection site pain (gluteal) were low for both treatment groups and decreased over the 24-week study. Injection site responses were uncommon (redness, swelling, induration).
Chengappa (2010)14 conducted a 15-month, randomized, open-label trial in adults with bipolar disorder (n=48)
RLAI 25-50 mg every 2 weeks (n=23)
or
Oral atypical antipsychotic (n=25)
For patients receiving RLAI:
  • Patient rating of injection site pain: rated as “0 (none)” or “2 (annoying)” in 12 patients; as “0” up to “4 (uncomfortable)” in 7 patients (with the majority of “3” or “4” scores reported at the initial injections); up to “6 (dreadful)” at the initial injections in 2 patients (which dropped to “0” at later injections); as “8 (horrible)” at the initial injection in 2 patients (which dropped to “1” to “3” at later injections). None of the patients reported scores of “9” or “10 (agonizing)”, and none of the patients discontinued due to injection site pain.
  • Nurse assessments of injection site redness, pain, swelling, and induration after each injection and before the next injection: the majority of scores were “0 (none)” for most variables, with occasional ratings of “1 (mild pain)”, and a rare rating of “2 (moderate pain)” in 3 patients.
Arunpongpaisal (2010)15 conducted a 12-week, open-label, nonrandomized trial in Thailand (n=184) in patients diagnosed with schizophrenia
RLAI 25-50 mg every 2 weeks (flexible dosing)
  • The mean score on the 10-cm VAS was 3.67±2.68 at the first injection and 2.74±2.55 at the 7th injection.
  • No injection site redness or swelling was reported.
Kulkarni (2010)16 conducted a survey assessing the intensity and duration of injection pain reported by patients currently receiving RLAI at two outpatient clinics in Australia (n=57).
Patients currently on a maintenance dose of RLAI participated in survey.
The median score on the VAS (0-100) was 38.0. The types of pain described were stinging (55.3%) throbbing (17.9%), aching (17.9%), burning (12.5%) and other (14.2%). The mean duration of pain was about 1 hour.
Gharabawi (2007)17 conducted a 1-year, prospective, open-label, single-arm, multicenter, pilot trial (n=87)
RLAI 50 mg every 2 weeks for 4 weeks then
RLAI 50 mg once monthly for 48 weeks
The incidence of injection site pain was 2.3%.
Lindenmayer (2007)18 described results from two extension trials. Trial A: 1-year open-label extension of a 12-week, double-blind, randomized, placebo-controlled trial (Kane 2003)8 Trial B: 1-year open-label extension of a 12-week open-label trial (Lindenmayer 2004)19 (n=100)
Trial A: RLAI 25, 50, or 75 mg every 2 weeks
Trial B: RLAI 25, 37.5, or 50 mg every 2 weeks median modal dose of 50 mg/ 2 weeks for both trials (flexible dose) (n=271)
Trial A:
Eight patients (3%) reported an adverse event at the injection site. Four patients experienced mild pain, and 1 patient each experienced mild bleeding, bruising, inflammation, and reaction.
Trial B:
One patient (1%) reported mild pain, and there were no reports of discontinuation due to an injection site adverse event.
Taylor (2009)20Taylor (2006)21 conducted a prospective, naturalistic evaluation of RLAI in patients with schizophrenia or schizoaffective disorder in an urban clinical setting in the UK.  Patients were evaluated at 6 months (n=250) and 3 years (n=211) or until treatment was discontinued.
RLAI 25, 37.5, 50, or 75 mg every 2 weeks
  • Over 6 months, RLAI treatment was discontinued due to pain at the injection site in 3 patients.
  • Over 3 years, RLAI treatment was discontinued due to pain at the injection site in 4 patients and an abscess at the injection site in 1 patient.
Kissling (2005)22 conducted a 1-year, open-label extension of a 6-month, nonrandomized, open-label trial (Moller 2005) described below (n=715)
RLAI 25 mg, 37.5 mg, or 50 mg every 2 weeks
Nine patients (1%) reported adverse events associated with the injection site; 8 were reported as injection pain.
Moller (2005)23 conducted a 6-month, open-label trial in patients with schizophrenia or other psychotic disorders (n=1876)
RLAI 25, 37.5, or 50 mg every 2 weeks
One percent of patients (n=27) reported adverse events associated with the injection site, of which 24 were reported as injection pain.
Lindenmayer (2004)19 conducted a 12-week, open-label trial in patients with schizophrenia switched from oral treatment with haloperidol, quetiapine, or olanzapine (n=141)
RLAI 25, 37.5, or 50 mg every 2 weeks
Mild pain at the injection site was reported by one patient in the prior quetiapine group following the first injection of risperidone long-acting.  No other injection site reactions were reported.
Fleischhacker (2003)24 conducted a 1-year, open-label trial in patients with schizophrenia (n=615)
RLAI 25, 50, or 75 mg every 2 weeks
Patient ratings of injection site pain
Median VAS score at 1st injection: 10
Median VAS score at 25th injection: 5 Investigator ratings
Investigators rated injection site pain as absent in 68% of patients at the first injection and absent in 80% of patients at the last injection.  Investigators rated redness as absent in 95% and 100% of patients, swelling as absent in 98% and 100%, and induration as absent in 100% and 93% at the first and last injections, respectively.
Retrospective Chart Review
Deslandes (2007)25 conducted a retrospective chart review of patients with schizophrenia during the first 18 months after initiation of RLAI (n=58)
RLAI (mean dose=39.2 mg) every 2 weeks
Of the 31 patients who discontinued treatment, 3 discontinued due to pain.
Abbreviations: INJ, injection; PALM, paliperidone palmitate; PBO, placebo; RLAI, risperidone long-acting injection; RIS, risperidone; SD, standard deviation; VAS, visual analog scale.aVAS=visual analogue scale (patient rated; 0=no pain, 100=unbearably painful, unless otherwise stated).bInvestigators rated the injection site for redness, pain, swelling and induration using a four-point scale (absent, mild, moderate, severe).

DELTOID ADMINISTRATION TRIALS


Deltoid Administration Trials
Lead Author/Trial Design
Treatment
Injection Site Reactionsa,b
Heres (2012)26 surveyed 60 schizophrenia patients (mean age: 43.2 years; 71.7% female) stabilized on gluteal RLAI therapy (≥6 months) who were offered a switch to deltoid injection in a standardized manner.
  • Baseline gluteal injection pain levels were obtained (1=no pain; 7=extreme pain)
  • Patients choosing to switch to deltoid injections were reassessed after 3 months.
  • In addition, preference of one application location over the other was recorded and differences between the two applications were assessed.
Baseline: Thirty-four (57%) patients chose to switch to deltoid injections.
  • Baseline demographics did not significantly differ between “switchers” and “non-switchers”.
  • At baseline, 6 out of 60 patients reported a meaningful level of pain associated with gluteal injections (pain score >4).
  • Leading decisions against switching to deltoid injections were “fear of increased pain” and “scar tissue/local dermal reactions in visible body parts”

Three-Month Follow-Up: Twenty-five of the thirty-four “switchers” participated in the follow-up assessment.
  • Of these 25 patients, 15 remained on deltoid injections, rating this route as “much better” (8 out of 15) or “somewhat better” (5 out of 15) then gluteal injections.
  • Of the 10 patients reverting back to gluteal injections, their leading reason was “increased pain through deltoid injections”. Compared to “switchers” remaining on deltoid injections, pain experienced in this group was significantly higher (P<0.01).
Quiroz (2011)27 Described results from 2 studies:
Single-dose study: Randomized, multicenter, two-way crossover study (n=170) measuring safety and pharmacokinetic properties by comparing single-dose DM (deltoid muscle) and GM (gluteal muscle) injections of RLAI in patients with chronic stable schizophrenia.
Multi-dose study:
Multi-dose, multicenter, safety study (n=53) evaluating DM injection of RLAI in patients with schizophrenia
Single-dose study:
RLAI 25 or 50 mg GM, 37.5 or 50 mg DM
Investigator-rated:
Single-dose study:
  • Injection-site reactions rating: mild: 51 (30%) moderate 9 (5%)
  • Incidences of injection site reactions were slightly higher following deltoid injection (37.5 mg: 21%; 50 mg; 27%) than gluteal injection (25 mg:12%; 50 mg 14%).
  • Based on TEAEs reported on injection-site reactions, the tolerability of RLAI was similar for a all dosage strengths regardless of the injection site.
  • Tenderness was the most common injection site reaction:
  • GM: 10% (both 25 & 50 mg)
  • DM 18% ( 37.5 mg) 19% ( 50 mg)
  • Redness:
  • GM 3% (25 mg); 6% (50 mg)
  • DM 5% (37.5 mg) 8% (50 mg)
  • Post-injection reactions occurred most frequently at 2 & 12 hours and resolved with no reports beyond Day 3 except for one occurrence of redness (50 mg; DM).
Multi-dose study: RLAI 37.5 or 50 mg DM every 2 weeks for 4 doses (flexible dosing)
Multi-dose study:
  • Mild injection site reactions were seen in 10 (19%) patients.
  • Post injection reactions were rated as “absent” 2 weeks after administration.
  • No moderate or severe reactions or dose-related differences were observed. No patients discontinued treatment due to site related TEAEs. Injection-site pain and injection-site reactions were reported as AEs by 7.5 and 1.9% of patients, respectively.

Patient-rated:
Single-dose study:
Mean change from baseline VAS scores (mm)
2 hours post injection:
25 mg GM: 1.1
50 mg GM: 0.5
37.5 mg DM: 3.4
50 mg DM: 1.1
  • Mean scores were comparable to baseline scores after 24 hours for all doses except 50 mg DM, for which scores normalized by 3 days after injection.
  • Multi-dose study:
  • Mean increase in VAS scores from pre-dose to post dose:
  • 50 mg DM: 5-10 mm
  • 37.5 mg DM: 1-3 mm
  • Mean scores returned to baseline by 2 weeks.
Abbreviations: DM, deltoid muscle; GM, gluteal muscle; RLAI, risperidone long-acting injection.aVAS=visual analogue scale (patient rated; 0=no pain, 100=unbearably painful).bInvestigators rated the injection site for redness, pain, swelling and induration using a four-point scale (absent, mild, moderate, severe).

CASE REPORTS

Saxena et al (2008)28 reported a case of a 58-year old man diagnosed with schizophrenia who had received several prior antipsychotic treatments, including fluphenazine decanoate from 1974-1980 and 1985-1987, and haloperidol decanoate from 1993-2007. For at least seven years, the patient would accept his biweekly injections only in his left arm, in the deltoid muscle, which resulted in the development in 2007 of three egg-shaped, hard, painful, noninfected lumpy nodules, which occupied approximately 75% of this area. In August 2007, the patient began treatment with RISPERDAL CONSTA administered in the deltoid muscle. The nodules decreased considerably in size, pain, and density, and by June 2008 they occupied approximately 12% of the area.

OTHER RELEVANT INFORMATION

Lindenmayer et al (2005)29 published results on injection site pain and patient satisfaction from both the Kane 20038 and Fleischhacker 200324 trials described above. The results in this publication included patients with schizophrenia and schizoaffective disorder. The citation is included in the reference section.

The reference section lists published letters to the editor that describe clinical experience with RISPERDAL CONSTA and injection site pain.30,31

LITERATURE SEARCH

A literature search of MEDLINE®, EMBASE®, BIOSIS Previews®, and DERWENT Drug File (and/or other resources, including internal/external databases) pertaining to this topic was conducted on 23 August 2023.

References

1 RISPERDAL CONSTA (risperidone long-acting injection) [Prescribing Information]. Titusville, NJ: Janssen Pharmaceuticals, Inc; https://imedicalknowledge.veevavault.com/ui/approved_viewer?token=7994-63671f9d-1035-4290-a18b-1c9102cceb15.
2 Pandina, G,  Lane R,  Gopal S, et al. A double-blind study of paliperidone palmitate and risperidone long-acting injectable in adults with schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry. 2011;35(1):218-226.
3 Alphs L,  Bossie CA,  Kern-Sliwa J, et al. Paliperidone palmitate and risperidone long-acting injectable in subjects with schizophrenia recently treated with oral risperidone or other oral antipsychotics. Neuropsychiatr Dis Treat. 2013;9:341-350.
4 Fu DJ,  Bossie CA,  Sliwa JK, et al. Paliperidone palmitate versus risperidone long-acting injection in markedly-to-severely ill schizophrenia subjects: onset of efficacy with recommended initiation regimens. Clin Schizophr Relat Psychoses. 2013;27:1-31.
5 Fu D-J,  Bossie CA,  Kern-Sliwa J, et al. Paliperidone palmitate versus oral risperidone and risperidone long-acting injection in patients with recently diagnosed schizophrenia: a tolerability and efficacy comparison. 2014;29(1):45-55.
6 Quiroz JA,  Yatham LN,  Palumbo JM, et al. Risperidone long-acting injectable monotherapy in the maintenance treatment of bipolar 1 disorder. Biol Psychiatry. 2010;68:156-162.
7 Chue P,  Eerdekens M,  Augustyns I, et al. Comparative efficacy and safety of long-acting risperidone and risperidone oral tablets. Eur Neuropsychopharmacol. 2005;15:111-117.
8 Kane JM,  Eerdekens M,  Lindenmayer JP, et al. Long-acting injectable risperidone: Efficacy and safety of the first long-acting atypical antipsychotic. Am J Psychiatry. 2003;160(6):1125-1132.
9 Bai YM,  Chen TT,  Chen JY, et al. Equivalent switching dose from oral risperidone to risperidone long-acting injection: a 48-week randomized, prospective, single-blind pharmacokinetic study. J Clin Psychiatry. 2007;68(8):1218-1225.
10 Bai YM,  Chen TT,  Wu B, et al. A comparative efficacy and safety study of long-acting risperidone injection and risperidone oral tablets among hospitalized patients: 12-week randomized, single-blind study. Pharmacopsychiatry. 2006;39:135-141.
11 Suzuki H,  Inoue Y, Gen K. A study of the efficacy and safety of switching from oral risperidone to risperidone long-acting injection in older patients with schizophrenia. Ther Adv Psychopharmacol. 2012;2(6):227-234.
12 Rosenheck RA,  Krystal JH,  Lew R, et al. Long-acting risperidone and oral antipsychotics in unstable schizophrenia. N Engl J Med. 2011;364(9):842-851.
13 Ruan L,  Hu S,  Huang M, et al. Efficacy and safety of long-acting risperidone on early onset schizophrenia in adolescent patients. African J Pharm Pharmacol. 2010;4(5):184-192.
14 Chengappa KNR,  Turkin SR,  Schlicht PJ, et al. A pilot, 15-month, randomized effectiveness trial of risperidone long-acting injection (RLAI) versus oral atypical antipsychotic agents (AAP) in persons with bipolar disorder. Acta Neuropsychiatr. 2010;22:68-80.
15 Arunpongpaisal S,  Srisurapanont M,  Kongsakon R, et al. Risperidone long-acting injection (RLAI): the 12-week efficacy and tolerability in Thai patients with chronic schizophrenia. J Med Assoc Thai. 2010;93(3):343-350.
16 Kulkarni J,  Dalton A,  Katz P, et al. A survey to assess pain associated with routine administration of intramuscular risperidone long-acting injection. Annual Meeting of the Australian Society for Psychiatric Research: Glial-Neuronal Networks in Neuropsychiatry; Dec 5-8, 2010; Sydney, Australia.
17 Gharabawi GM,  Gearhart NC,  Lasser RA, et al. Maintenance therapy with once-monthly administration of long-acting injectable risperidone in patients with schizophrenia or schizoaffective disorder: a pilot study of an extended dosing interval. Ann Gen Psychiatry. 2007;6:3.
18 Lindenmayer JP,  Khan A,  Eerdekens M, et al. Long-term safety and tolerability of long-acting injectable risperidone in patients with schizophrenia or schizoaffective disorder. Eur Neuropsychopharmacol. 2007;17:138-144.
19 Lindenmayer JP,  Eerdekens E,  Berry SA, et al. Safety and efficacy of long-acting risperidone in schizophrenia: A 12-week, multicenter, open-label study in stable patients switched from typical and atypical oral antipsychotics. J Clin Psychiatry. 2004;65(8):1084-1089.
20 Taylor DM,  Fischetti C,  Sparshatt A, et al. Risperidone long-acting injection: a prospective 3-year analysis of its use in clinical practice. J Clin Psychiatry. 2009;70:196-200.
21 Taylor DM,  Young C, Patel MX. Prospective 6-month follow-up of patients prescribed risperidone long-acting injection: Factors predicting favourable outcome. Int J Neuropsychopharmacol. 2006;9:685-694.
22 Kissling W,  Heres S,  Lloyd K, et al. Direct transition to long-acting risperidone - analysis of long-term efficacy. J Psychopharmacol. 2005;19(5)(suppl 1):15-21.
23 Moller H,  Llorca P,  Sacchetti E, et al. Efficacy and safety of direct transition to risperidone long-acting injectable in patients treated with various antipsychotic therapies. Int Clin Psychopharmacol. 2005;20:121-130.
24 Fleischhacker WW,  Eerdekens M,  Karcher K, et al. Treatment of schizophrenia with long-acting injectable risperidone: a 12-month open-label trial of the first long-acting second-generation antipsychotic. J Clin Psychiatry. 2003;64(10):1250-1257.
25 Deslandes PN,  Thomas A,  Faulconbridge GM, et al. Experience with risperidone long-acting injection: results of a naturalistic observation study. Int J Psychiatry Clin Pract. 2007;11:207-211.
26 Heres S,  Frobose T,  Hamann J, et al. Patients' acceptance of the deltoid application of risperidone long-acting injection. Eur Neuropsychopharmacol. 2012;22(12):897-901.
27 Quiroz JA,  Rusch S,  Thyssen A, et al. Deltoid injections of risperidone long-acting injectables in patients with schizophrenia. Innov Clin Neurosci. 2011;8(6):20-28.
28 Saxena A,  Grace J,  Olympia JL, et al. Risperidone long-acting injections: successful alternative deltoid muscle injections for refractory schizophrenia. Psychiatry. 2008;5(9):40-42.
29 Lindenmayer JP,  Jarboe K,  Bossie CA, et al. Minimal injection site pain and high patient satisfaction during treatment with long-acting risperidone. Int Clin Psychopharmacol. 2005;20:213-221.
30 Pinninti NR, Mago R. Injection site pain with long-acting risperidone. J Clin Psychiatry. 2005;66(5):656-657.
31 Lindenmayer JP,  Eerdekens E, Eerdekens M. Dr. Lindenmayer and colleagues reply. J Clin Psychiatry. 2005;66(5):657.